28231 Results for: "Biotium"

Supplier: Biotium

The MUC6 gastric mucin is a secreted glycoprotein that plays an essential role in epithelial cyto-protection from acid, proteases, pathogenic microorganisms, and mechanical trauma in the gastrointestinal tract. Mucin 6 expression is highest in the stomach and gall bladder, with lower expression in the terminal ileum and right colon. In gastric cancer, Mucin 6 has an altered expression. In normal stomach, Mucin 6 is associated with Lewis type 2; Mucin 6 is also expressed in gastric metaplasia, duodenum and pancreas. Mucin 6 is a secretory mucin, located in the deeper mucosal folds of human gall bladder, and its expression is altered with increasing degrees of inflammation.

Supplier: Biotium

Ten to forty percent of the patients with acquired immunodeficiency syndrome (AIDS) develop cytomegalovirus (CMV) infections. In some patients with AIDS, CMV is detected in the bronchoalveolar lavage fluid (BALF), urine, and other specimens, even when there are no symptoms of CMV disease. An indicator of active CMV infection is needed to facilitate the diagnosis of CMV disease in patients with AIDS or HIV infection. CMV p65 antigen was detected in the leukocytes of both the peripheral blood and BALF during the early phase of CMV disease.

Supplier: Biotium

Anti-CK8 Mouse Monoclonal Antibody (APC) [clone: CMV100]

Supplier: Biotium

CD17 is an intermediate glycosphingolipid from the metabolism of higher gangliosides that localizes to sphingolipid-sterol rafts. CD17 is detectable in monocytes, granulocytes, basophils, platelets, a subset of peripheral B cells (CD19 ) and tonsil dendritic cells. It is rapidly down regulated on activated granulocytes and is upregulated on IL-2 activated T lymphocytes. CD17 binds to bacteria and may function in phagocytosis. VEGF-treated endothelial cells can produce CD17, which can then mediate signaling toward PECAM-1 expression and angiogenesis. Tumor necrosis factor alpha (TNFa)-induced astrogliosis (astrocyte proliferation and glial fibrillary acidic protein (GFAP) upregulation) in response to neuro-inflammation (i.e. spinal cord injury) causes an increase in intracellular levels of CD17. Aberrant levels of glycosphingolipids are a feature of cancer cells and may influence integrin clustering and internalization.

Supplier: Biotium

This MAb recognizes basic (Type II or HMW) cytokeratins, which include 67 kDa (CK1); 64 kDa (CK3); 59 kDa (CK4); 58 kDa (CK5); 56 kDa (CK6); 52 kDa (CK8). Twenty human keratins are resolved with two-dimensional gel electrophoresis into acidic (pI 6.0) subfamilies. The acidic keratins have molecular weights (MW) of 56.5, 55, 51, 50, 50 , 48, 46, 45, and 40 kDa. MAb AE3 recognizes the 65-67, 64, 59, 58, 56, and 52 kDa keratins of basic subfamily. Many studies have shown the usefulness of keratins as markers in cancer research and tumor diagnosis. AE1/AE3 is a broad spectrum anti pan-keratin antibody cocktail, which differentiates epithelial tumors from non-epithelial tumors e.g. squamous vs. adenocarcinoma of the lung, liver carcinoma, breast cancer, and esophageal cancer.

Supplier: Biotium

Cytokeratin 8 (CK8) belongs to the type II (or B or basic) subfamily of high molecular weight cytokeratins and exists in combination with cytokeratin 18 (CK18). CK8 is primarily found in the non-squamous epithelia and is present in majority of adenocarcinomas and ductal carcinomas. It is absent in squamous cell carcinomas. Hepatocellular carcinomas are defined by the use of antibodies that recognize only cytokeratin 8 and 18. CK8 exists on several types of normal and neoplastic epithelia, including many ductal and glandular epithelia such as colon, stomach, small intestine, trachea, and esophagus as well as in transitional epithelium. Anti-CK8 does not react with skeletal muscle or nerve cells. Epithelioid sarcoma, chordoma, and adamantinoma show strong positivity corresponding to that of simple epithelia (with antibodies against CK8, CK18 and CK19). Reportedly, anti-CK8 is useful for the differentiation of lobular (ring-like, perinuclear) from ductal (peripheral-predominant) carcinoma of the breast.

Supplier: Biotium

This MAb recognizes basic (Type II or HMW) cytokeratins, which include 67 kDa (CK1); 64 kDa (CK3); 59 kDa (CK4); 58 kDa (CK5); 56 kDa (CK6); 52 kDa (CK8). Twenty human keratins are resolved with two-dimensional gel electrophoresis into acidic (pI 6.0) subfamilies. The acidic keratins have molecular weights (MW) of 56.5, 55, 51, 50, 50 , 48, 46, 45, and 40 kDa. Many studies have shown the usefulness of keratins as markers in cancer research and tumor diagnosis.

Supplier: Biotium

This antibody recognizes an antigen associated with the nuclear membrane expressed in human cells. It can be used to stain the nuclear membrane in cell or tissue preparations and can be used as a marker of the nuclear membrane in subcellular fractions. It produces a ring pattern around the nucleus of cells of normal and malignant cells and may be used to stain the nuclear membrane of cells in fixed or frozen tissue sections. ,The nuclear envelope (also known as the perinuclear envelope, nuclear membrane, nucleolemma or karyotheca) is the double membrane of the nucleus that encloses genetic material in eukaryotic cells. It separates the contents of the nucleus (DNA in particular) from the cytosol (cytoplasm). Numerous nuclear pores are present on the nuclear envelope to facilitate and regulate the exchange of materials (for example, proteins and RNA) between the nucleus and the cytoplasm. The space between the two membranes that make up the nuclear envelope is called the perinuclear space (also called the perinuclear cisterna), and is usually about 20 - 40 nm wide. Each of the two membranes is composed of a lipid bilayer. The outer membrane is continuous with the rough endoplasmic reticulum. The inner membrane is erected upon the nuclear lamina, a network of intermediate filaments made of lamin, that plays a role in mitosis and meiosis. The type of lamins present are A, B1, B2, and C. The nuclear envelope may also play a role in the disposition of chromatin inside the nucleus. The lamina acts as a site of attachment for chromosomes. It also acts like a shield for the nucleus. During prophase in mitosis, the chromatids begin condensing to form chromosomes, and the nuclear envelope begins to disintegrate. During metaphase, the nuclear envelope is completely disintegrated, and the chromosomes can be pulled apart as chromatids by the spindle fibers.

Supplier: Biotium

Cyclins, regulatory subunits, which associate with kinases, control many of the important steps in cell cycle progression. The Cdc2 protein kinase (p34Cdc2) exhibits protein kinase activity in vitro and exists in a complex with both cyclin B and a protein homologous to p13SUC1. Cdc2 kinase is the active subunit of the M phase promoting factor (MPF) and the M phase-specific Histone H1 kinase. The p34Cdc2/cyclin B complex is required for the G2 to M transition. An additional cell cycle-dependent protein kinase, termed p55cdc, exhibits a high degree of homology with the S. cerevisiae proteins Cdc20 and Cdc4. The p55cdc transcript is readily detectable in a variety of cultured cell lines in growth phase, but disappears when cell growth is chemically arrested.

Supplier: Biotium

Cyclins, regulatory subunits, which associate with kinases, control many of the important steps in cell cycle progression. The Cdc2 protein kinase (p34Cdc2) exhibits protein kinase activity in vitro and exists in a complex with both cyclin B and a protein homologous to p13SUC1. Cdc2 kinase is the active subunit of the M phase promoting factor (MPF) and the M phase-specific Histone H1 kinase. The p34Cdc2/cyclin B complex is required for the G2 to M transition. An additional cell cycle-dependent protein kinase, termed p55cdc, exhibits a high degree of homology with the S. cerevisiae proteins Cdc20 and Cdc4. The p55cdc transcript is readily detectable in a variety of cultured cell lines in growth phase, but disappears when cell growth is chemically arrested.

Supplier: Biotium

CD19 is a transmembrane glycoprotein that contains two extracellular immunoglobulin-like domains. CD19 is present in both benign and malignant B-cells and is considered to be the most reliable surface marker of this lineage over a wide range of maturational stages. In normal lymphoid tissue, CD19 is observed in germinal centers, in mantle zone cells, and in scattered cells of the inter-follicular areas. Anti-CD19 exhibits an overall immunoreactivity pattern similar to those of the antibodies against CD20 and CD22. However, in contrast to CD20, expression of CD19 is continuous throughout B-cell development and through terminal differentiation of B-cells into plasma cells. Anti-CD19 positivity is seen in the vast majority of B-cell neoplasms commonly at a lower intensity than normal B-cell counterparts. Plasma cell neoplasms are nearly always negative, as are T-cell neoplasms.

Supplier: Biotium

Recognizes a protein of 30-33 kDa, which is identified as CD20 (Workshop V; Code CD20.4). It is a non-Ig differentiation antigen of B-cells and its expression is restricted to normal and neoplastic B-cells, being absent from all other leukocytes and tissues. CD20 is expressed by pre B-cells and persists during all stages of B-cell maturation but is lost upon terminal differentiation into plasma cells. The protein passes through the membrane 4 times with both ends in cytoplasm and exposes one short and one longer loop to the external environment. CD20 is not glycosylated in resting B-cells and its cytoplasmic domains are differentially phosphorylated upon activation. It acts as calcium channel involved in B cell activation and cell cycle progression.

Supplier: Biotium

CD19 is a transmembrane glycoprotein that contains two extracellular immunoglobulin-like domains. CD19 is present in both benign and malignant B-cells and is considered to be the most reliable surface marker of this lineage over a wide range of maturational stages. In normal lymphoid tissue, CD19 is observed in germinal centers, in mantle zone cells, and in scattered cells of the inter-follicular areas. Anti-CD19 exhibits an overall immunoreactivity pattern similar to those of the antibodies against CD20 and CD22. However, in contrast to CD20, expression of CD19 is continuous throughout B-cell development and through terminal differentiation of B-cells into plasma cells. Anti-CD19 positivity is seen in the vast majority of B-cell neoplasms commonly at a lower intensity than normal B-cell counterparts. Plasma cell neoplasms are nearly always negative, as are T-cell neoplasms.

Supplier: Biotium

This MAb is specific to heavy chain of IgA and shows minimal cross-reaction with heavy chains of other immunoglobulins. It is reactive with both IgA1 and IgA2 subclasses of Alpha heavy chain. It reacts with the third constant domain (CH3) of the alpha chain of IgA molecules. Immunoglobulins are four-chain, Y-shaped, monomeric structures comprised of two identical heavy chains and two identical light chains held together through inter-chain disulfide bonds. The chains form two domains, the Fab (antigen binding) fragment and the Fc (constant) fragment. Immunoglobulin A (IgA) is the main protein of the mucosal immune system. It is generated by B-cells in gut-associated lymphoid tissues. Daily production of IgA exceeds that of any of the other immunoglobulins.IgA exists mainly in dimers but can also exist as polymers or as monomers. Dimers and polymers contain a joining (J) chain that can be bound by the polymeric immunoglobulin receptor (pIgR) for transportation of the molecule to mucosal surfaces. The most common feature of plasmacytomas, and certain non-Hodgkin's lymphomas is the restricted expression of a single heavy chain class. Demonstration of clonality in lymphoid infiltrates indicates that the infiltrate is clonal and therefore malignant.

Supplier: Biotium

Recognizes a polypeptide which is identified as insulin, a 51-amino acid polypeptide composed of A and B chains connected through the C-peptide. Proinsulin, which has very little biological activity, is cleaved by proteases within its cell of origin into the insulin molecule and the C-terminal basic residue. Insulin enhances membrane transport of glucose, amino acids, and certain ions. It also promotes glycogen storage, formation of triglycerides, and synthesis of proteins and nucleic acids. Deficiency of insulin results in diabetes mellitus. The main storage site for insulin is the pancreatic islets. Antibodies to insulin are important as beta-cell and insulinoma marker.

Supplier: Biotium

The epitope of this MAb is located between aa343-357 (ELAI kDaNAKLSELE). Cytokeratin 8 (CK8) belongs to the type II (or B or basic) subfamily of high molecular weight cytokeratins and exists in combination with cytokeratin 18 (CK18). CK8 is primarily found in the non-squamous epithelia and is present in majority of adenocarcinomas and ductal carcinomas. It is absent in squamous cell carcinomas. Hepatocellular carcinomas are defined by the use of antibodies that recognize only cytokeratin 8 and 18. CK8 exists on several types of normal and neoplastic epithelia, including many ductal and glandular epithelia such as colon, stomach, small intestine, trachea, and esophagus as well as in transitional epithelium. Anti-CK8 does not react with skeletal muscle or nerve cells. Epithelioid sarcoma, chordoma, and adamantinoma show strong positivity corresponding to that of simple epithelia (with antibodies against CK8, CK18 and CK19). Reportedly, anti-CK8 is useful for the differentiation of lobular (ring-like, perinuclear) from ductal (peripheral-predominant) carcinoma of the breast.

Supplier: Biotium

Recognizes a protein of 40 kDa, identified as CD7 (Workshop IV; Code T155). CD7 is a member of the immunoglobulin gene superfamily. Its N-terminal amino acids 1-107 are highly homologous to Ig kappa-L chains whereas the carboxyl-terminal region of the extracellular domain is proline-rich and has been postulated to form a stalk from which the Ig domain projects. CD7 is expressed on the majority of immature and mature T-lymphocytes, and T cell leukemia. It is also found on natural killer cells, a small subpopulation of normal B cells and on malignant B cells. Cross-linking surface CD7 positively modulates T cell and NK cell activity as measured by calcium fluxes, expression of adhesion molecules, cytokine secretion and proliferation. CD7 associates directly with phosphoinositol 3'-kinase. CD7 ligation induces production of D-3 phosphoinositides and tyrosine phosphorylation.

Supplier: Biotium

This MAb recognizes protein of 26 kDa-60 kDa, which is identified as CD63. Its epitope is different from that of MAb LAMP3/529. The tetraspanins are integral membrane proteins expressed on cell surface and granular membranes of hematopoietic cells and are components of multi-molecular complexes with specific integrins. The tetraspanin CD63 is a lysosomal membrane glycoprotein that translocates to the plasma membrane after platelet activation. CD63 is expressed on activated platelets, monocytes and macrophages, and is weakly expressed on granulocytes, T cell and B cells. It is located on the basophilic granule membranes and on the plasma membranes of lymphocytes and granulocytes. CD63 is a member of the TM4 superfamily of leukocyte glycoproteins that includes CD9, CD37 and CD53, which contain four transmembrane regions. CD63 may play a role in phagocytic and intracellular lysosome-phagosome fusion events. CD63 deficiency is associated with Hermansky-Pudlak syndrome and is strongly expressed during the early stages of melanoma progression.

Supplier: Biotium

This MAb recognizes protein of 26 kDa-60 kDa, which is identified as CD63. Its epitope is different from that of MAb LAMP3/529. The tetraspanins are integral membrane proteins expressed on cell surface and granular membranes of hematopoietic cells and are components of multi-molecular complexes with specific integrins. The tetraspanin CD63 is a lysosomal membrane glycoprotein that translocates to the plasma membrane after platelet activation. CD63 is expressed on activated platelets, monocytes and macrophages, and is weakly expressed on granulocytes, T cell and B cells. It is located on the basophilic granule membranes and on the plasma membranes of lymphocytes and granulocytes. CD63 is a member of the TM4 superfamily of leukocyte glycoproteins that includes CD9, CD37 and CD53, which contain four transmembrane regions. CD63 may play a role in phagocytic and intracellular lysosome-phagosome fusion events. CD63 deficiency is associated with Hermansky-Pudlak syndrome and is strongly expressed during the early stages of melanoma progression.

Supplier: Biotium

This MAb recognizes protein of 26 kDa-60 kDa, which is identified as CD63. Its epitope is different from that of MAb LAMP3/529. The tetraspanins are integral membrane proteins expressed on cell surface and granular membranes of hematopoietic cells and are components of multi-molecular complexes with specific integrins. The tetraspanin CD63 is a lysosomal membrane glycoprotein that translocates to the plasma membrane after platelet activation. CD63 is expressed on activated platelets, monocytes and macrophages, and is weakly expressed on granulocytes, T cell and B cells. It is located on the basophilic granule membranes and on the plasma membranes of lymphocytes and granulocytes. CD63 is a member of the TM4 superfamily of leukocyte glycoproteins that includes CD9, CD37 and CD53, which contain four transmembrane regions. CD63 may play a role in phagocytic and intracellular lysosome-phagosome fusion events. CD63 deficiency is associated with Hermansky-Pudlak syndrome and is strongly expressed during the early stages of melanoma progression.

Supplier: Biotium

This antibody recognizes a protein of about 60 kDa, which is identified as human UGT1A9. It does not cross-react with the other UGT1A isoforms including UGT1A7, UGT1A8, and UGT1A10 and shows a high degree of specificity. UGT1A9 is a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This MAb binds to human hepatocytes and the majority of human hepatocellular carcinomas (HCC s). In frozen sections, it stains hepatic cells and may be used as a marker of the liver. This MAb also binds to cell preparations of hepatocellular carcinoma biopsies or cell lines.

Supplier: Biotium

Mucin 5AC glycoprotein (MUC5AC) is a 641 kDa glycoprotein belonging to the superfamily of mucins. Mucins are high molecular weight glycoproteins produced by epithelial cells and can be divided into two families; secretory mucins and membrane bound mucins. MUC5AC is a mucus-forming secreted mucin that is found in normal gastric and tracheo-bronchial mucosa, but absent from normal colon. MUC5AC expression is present in primary ovarian mucinous cancer but usually absent in colorectal adenocarcinoma, thus showing an expression pattern opposite to MUC2. Together with a panel of antibodies, Anti-MUC5AC may be useful for differential identification of primary mucinous ovarian tumors from colon adenocarcinoma metastatic to the ovary. MUC5AC antibodies may also be useful for identification of intestinal metaplasia as well as in the identification of pancreatic carcinoma and pre-cancerous changes vs. normal pancreas.

Supplier: Biotium

Mucin 5AC glycoprotein (MUC5AC) is a 641 kDa glycoprotein belonging to the superfamily of mucins. Mucins are high molecular weight glycoproteins produced by epithelial cells and can be divided into two families; secretory mucins and membrane bound mucins. MUC5AC is a mucus-forming secreted mucin that is found in normal gastric and tracheo-bronchial mucosa, but absent from normal colon. MUC5AC expression is present in primary ovarian mucinous cancer but usually absent in colorectal adenocarcinoma, thus showing an expression pattern opposite to MUC2. Together with a panel of antibodies, Anti-MUC5AC may be useful for differential identification of primary mucinous ovarian tumors from colon adenocarcinoma metastatic to the ovary. MUC5AC antibodies may also be useful for identification of intestinal metaplasia as well as in the identification of pancreatic carcinoma and pre-cancerous changes vs. normal pancreas.

Supplier: Biotium

This MAb recognizes protein of 26 kDa-60 kDa, which is identified as CD63. Its epitope is different from that of MAb LAMP3/529. The tetraspanins are integral membrane proteins expressed on cell surface and granular membranes of hematopoietic cells and are components of multi-molecular complexes with specific integrins. The tetraspanin CD63 is a lysosomal membrane glycoprotein that translocates to the plasma membrane after platelet activation. CD63 is expressed on activated platelets, monocytes and macrophages, and is weakly expressed on granulocytes, T cell and B cells. It is located on the basophilic granule membranes and on the plasma membranes of lymphocytes and granulocytes. CD63 is a member of the TM4 superfamily of leukocyte glycoproteins that includes CD9, CD37 and CD53, which contain four transmembrane regions. CD63 may play a role in phagocytic and intracellular lysosome-phagosome fusion events. CD63 deficiency is associated with Hermansky-Pudlak syndrome and is strongly expressed during the early stages of melanoma progression.

Supplier: Biotium

Recognizes a protein of 40 kDa, identified as CD7 (also known as gp40, Leu9). CD7 is a member of the immunoglobulin gene superfamily. Its N-terminal amino acids 1-107 are highly homologous to Ig kappa-L chains whereas the carboxyl-terminal region of the extracellular domain is proline-rich and has been postulated to form a stalk from which the Ig domain projects. CD7 is expressed on the majority of immature and mature T-lymphocytes, and T cell leukemia. It is also found on natural killer cells, a small subpopulation of normal B cells and on malignant B cells. Cross-linking surface CD7 positively modulates T cell and NK cell activity as measured by calcium fluxes, expression of adhesion molecules, cytokine secretion and proliferation. CD7 associates directly with phosphoinositol 3'-kinase. CD7 ligation induces production of D-3 phosphoinositides and tyrosine phosphorylation.

Supplier: Biotium

This MAb recognizes protein of 26 kDa-60 kDa, which is identified as CD63. Its epitope is different from that of MAb LAMP3/529. The tetraspanins are integral membrane proteins expressed on cell surface and granular membranes of hematopoietic cells and are components of multi-molecular complexes with specific integrins. The tetraspanin CD63 is a lysosomal membrane glycoprotein that translocates to the plasma membrane after platelet activation. CD63 is expressed on activated platelets, monocytes and macrophages, and is weakly expressed on granulocytes, T cell and B cells. It is located on the basophilic granule membranes and on the plasma membranes of lymphocytes and granulocytes. CD63 is a member of the TM4 superfamily of leukocyte glycoproteins that includes CD9, CD37 and CD53, which contain four transmembrane regions. CD63 may play a role in phagocytic and intracellular lysosome-phagosome fusion events. CD63 deficiency is associated with Hermansky-Pudlak syndrome and is strongly expressed during the early stages of melanoma progression.

Supplier: Biotium

This MAb reacts with the rod domain of human cytokeratin-19 (CK19), a polypeptide of 40 kDa. Its epitope maps between amino acid 312-335. CK19 is expressed in sweat gland, mammary gland ductal and secretory cells, bile ducts, gastrointestinal tract, bladder urothelium, oral epithelia, esophagus, and ectocervical epithelium. Anti-CK19 reacts with a wide variety of epithelial malignancies including adenocarcinomas of the colon, stomach, pancreas, biliary tract, liver, and breast. Perhaps the most useful application is the identification of thyroid carcinoma of the papillary type, although 50%-60% of follicular carcinomas are also labeled. Anti-CK19 is a useful marker for detection of tumor cells in lymph nodes, peripheral blood, bone marrow and breast cancer.

Supplier: Biotium

Anti-CD57 marks a subset of lymphocytes known as natural killer (NK) cells. Follicular center cell lymphomas often contain many NK cells within the neoplastic follicles. Anti-CD57 also stains neuroendocrine cells and their derived tumors, including carcinoid tumor and medulloblastoma. Anti-CD57 can also be useful in separating type B3 thymoma from thymic carcinoma when combined with a panel that includes antibodies against GLUT1, CD5, and CEA.

Supplier: Biotium

ZAP70 is a 70 kDa protein tyrosine kinase found in T-cells and natural killer cells. Control of this protein translation is via the IgVH gene.In Western blotting of whole cell lysates of normal peripheral blood mononuclear cells, the antibody labels a band corresponding to ZAP70. In Western blotting of whole cell lysates of CD19-positive purified leukemia cells from patients with Ig-unmutated and Ig-mutated CLL, the antibody labels a band corresponding to ZAP70 in the Ig-unmutated CLL samples, whereas no band is observed in the Ig-mutated CLL samples. In Western blotting of cell lysates of Jurkat cells (T-lymphoblastic cell line), the antibody labels a band of 70 kDa protein. In Western blotting of cell lysates of A431 cells (carcinoma cell line), no band is observed. ZAP70 protein is expressed in leukemic cells of approximately 25% of chronic lymphocytic leukemia (CLL) cases as well. Anti-ZAP70 expression is an excellent surrogate marker for the distinction between the Ig-mutated (anti-ZAP70 negative) and Ig-unmutated (anti-ZAP70 positive) CLL subtypes and can identify patient groups with divergent clinical courses. The anti-ZAP70 positive Ig-unmutated CLL cases have been shown to have a poorer prognosis.

Supplier: Biotium

ZAP70 is a 70 kDa protein tyrosine kinase found in T-cells and natural killer cells. Control of this protein translation is via the IgVH gene.In Western blotting of whole cell lysates of normal peripheral blood mononuclear cells, the antibody labels a band corresponding to ZAP70. In Western blotting of whole cell lysates of CD19-positive purified leukemia cells from patients with Ig-unmutated and Ig-mutated CLL, the antibody labels a band corresponding to ZAP70 in the Ig-unmutated CLL samples, whereas no band is observed in the Ig-mutated CLL samples. In Western blotting of cell lysates of Jurkat cells (T-lymphoblastic cell line), the antibody labels a band of 70 kDa protein. In Western blotting of cell lysates of A431 cells (carcinoma cell line), no band is observed. ZAP70 protein is expressed in leukemic cells of approximately 25% of chronic lymphocytic leukemia (CLL) cases as well. Anti-ZAP70 expression is an excellent surrogate marker for the distinction between the Ig-mutated (anti-ZAP70 negative) and Ig-unmutated (anti-ZAP70 positive) CLL subtypes and can identify patient groups with divergent clinical courses. The anti-ZAP70 positive Ig-unmutated CLL cases have been shown to have a poorer prognosis.