You searched for: Proteins and Peptides

Supplier: STEMCELL Technologies

Butyrophilin 1A1 (BTN1A1) is a glycoprotein belonging to the butyrophilin (BTN) family which collectively modulates immune responses, through excitatory and inhibitory signals targeting immune cells. Butyrophilins are composed of two extracellular immunoglobulin domains and a transmembrane region, with a conserved B30.2 domain (PRYSPRY) that is present in most members (Malinowska et al.). BTN1A1, along with BTN2A2, has been shown to inhibit the proliferation of CD4+ and CD8+ T cells, modify T cell metabolism, and affect the expression of IL-2 and IFN-γ (Smith et al.). Due to these modulatory effects on T cells, BTN1A1 may have a role in inhibiting the development of autoimmune diseases (Stefferl et al.). BTN1A1 is also expressed in mammary glands and is required for the secretion of milk lipids during lactation (Ogg et al.). This protein contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, Serpin A12 from STEMCELL comes lyophilised with ≥92% purity, and is verified by LAL analysis to ensure endotoxin levels are ≤1,0 EU/μg protein.

Supplier: Sino Biological

The processed form of human IL1α (NP_000566.3) (Ser 113-Ala 271) was expressed and purified.

Supplier: STEMCELL Technologies

Nerve growth factor (NGF)-beta is a prototypical member of the neurotrophin family and has a role in the survival and growth of neural cells, regulating cell growth, promoting differentiation into neurons, and neuron migration. The beta subtype of NGF is biologically active in comparison to the alpha-2 and gamma-2 subtypes. NGF-beta in its secreted form can bind to tyrosine kinase A (trkA) receptor with high affinity and to p75 (NTR) with low affinity (Levi and Alemà; Sofroniew et al.). NGF has been shown to possess pro-inflammatory and pro-fibrogenic properties (Micera et al.). It has also been shown that overexpression of NGF-beta promotes differentiation of bone marrow mesenchymal stem cells into neurons through regulation of AKT and MAPK pathways (Yuan et al.). This product is animal component-free.

Supplier: STEMCELL Technologies

Influenza (HLA class I control) peptide pool is a lyophilised mixture of 17 peptides from the influenza virus. The pool consists of defined HLA class I-restricted T cell epitopes, and can be used as an antigen-specific positive control to stimulate T cells.

Supplier: Sino Biological

A DNA sequence encoding the extracellular domain of mouse EpCAM (NP_032558.2) (Met 1-Thr 266) was expressed, with a polyhistidine tag at the C-terminus.

Supplier: ACROBIOSYSTEMS

Cynomolgus Fc gamma RIIA / CD32a Protein, His Tag (SPR & BLI & HPLC verified).

Supplier: STEMCELL Technologies

Use hepassocin to bind to lymphocyte-activation gene 3 (LAG-3) in an MHC class II independent manner, and inhibit antigen-specific T-cell activation (Wang et al.). Hepassocin is known to play a restorative role in the liver, reducing apoptosis and accelerating hepatocyte proliferation in vivo (Li et al.). In addition to these hepatoprotective effects, studies have shown that hepassocin expression is upregulated in gastric cancer tissues (Zhang et al.) and in breast cancer cells (Du et al.), suggesting it has potential to predict cancer disease progression. Hepassocin is a member of the fibrinogen superfamily, whose members share a fibrinogen domain at their C-terminus. It is predominantly expressed in the liver, and weakly in the pancreas (Hara et al.), and is secreted as a homodimer that consists of 312 amino acids. Hepassocin is an acute-phase reactant whose expression in HepG2 cells has been shown to be regulated by IL-6 (Liu and Ukomadu). This protein product contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, hepassocin from STEMCELL comes lyophilised with ≥87% purity, and endotoxin levels are verified to be ≤1,0 EU/μg protein.

Supplier: Sino Biological

A DNA sequence encoding the amino acid residues (Met 1-Cys 213) of the human IL2 receptor α chain (NP_000408.1) precursor was expressed with C-terminal fused human IgG1 Fc region.

Supplier: STEMCELL Technologies

Interleukin 6 receptor (IL-6R) alpha is a type I transmembrane glycoprotein that forms a complex with type I transmembrane signal transducer protein gp130 (CD130) and mediates the biological activities of IL-6. IL-6 binds to the membrane-bound non-signaling IL-6R alpha (mIL-6R), and the complex binds to two molecules of gp130 and leads to ‘classical’ IL-6-signal transduction, which includes activation of JAK/STAT, ERK, and PI3K signal transduction pathways (Scheller et al.). In contrast, a soluble form of IL-6R alpha (sIL-6R), which comprises the extracellular portion of the receptor, binds to the secreted IL-6 to form a complex that promotes bioavailability of IL-6. The complex of IL-6 and sIL-6R can bind to gp130 on cells that do not express the IL-6R and are unresponsive to IL-6. This process is known as trans-signaling (Hunter and Jones; Rose-John S). sIL-6R regulates both local and systemic IL-6-mediated events. Elevated levels of sIL-6R have been documented in several disease conditions such as rheumatoid arthritis, myeloma, and Crohn’s disease (Jones et al.; Mihara et al.).

Supplier: STEMCELL Technologies

Complement factor D is a component of the alternative pathway of the complement system and part of the innate immune system, playing a vital role in the initiation and amplification of complement activation, in order to defend against infection (Barratt and Weitz). A serine protease belonging to the S1 peptidase family, complement factor D is secreted by adipocytes into circulating blood, and is also expressed by macrophages and monocytes (White et al.). In the initiation phase of the complement pathway, complement factor D cleaves complement factor B (bound to component C3) to produce a complex known as C3 convertase. During the amplification phase, complement factor D cleaves complement factor B (bound to component C3b) to produce the C3bBb convertase, and is involved in the propagation of complement activation. In addition to its immunological role, complement factor D is involved in other physiological processes, such as the efficient clearing of damaged cell debris by phagocytes following acute liver injury (Cresci et al.). Complement factor D deficiency is associated with an increased susceptibility to pathogens like Neisseria meningitidis (Biesma et al.). This protein contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, complement factor D from STEMCELL comes lyophilised with ≥94% purity, and is verified by LAL analysis to ensure endotoxin levels are ≤1,0 EU/μg protein.

Supplier: STEMCELL Technologies

Platelet-derived growth factor (PDGF) is a dimeric glycoprotein consisting of two disulfide bridge-stabilized polypeptide chains, A and B, which are assembled as heterodimers (PDGF-AB) or homodimers (PDGF-AA and PDGF-BB) (Fretto et al.; Westermark and Heldin). PDGF signals through the receptor tyrosine kinases PDGFRalpha and PDGFRbeta. It has been shown that PDGF-induced migration involves signaling pathways involving MEK/ERK, EGFR, Src, and PI3K/AKT (Kim et al.). PDGF is a potent mitogen for cells of mesenchymal origin- like fibroblasts, glial cells, and vascular smooth muscle cells. PDGF has been implicated in pathogenesis of atherosclerosis, glomerulonephritis, cancer, and in the contraction of vascular smooth muscle cells of rat aortic tissues (Fretto et al.; Sachinidis et al.). It has been shown that PDGF-AB together with 5-Azacytidine (Catalog #72012), induces the conversion of mature bone and fat cells into tissue-regenerative multipotent stem cells (Chandrakanthan et al.).

Supplier: STEMCELL Technologies

Human Interleukin 4 (IL-4) is important for immune responses to helminth infection as well as in allergic responses (Olpihant et al.). The IL-4 receptor consists of a heterodimer of IL-4Ra and common gamma chain. IL-4 receptor engagement leads to the activation of JAK1/3 and the recruitment of STAT6 and IRS1/2 (Nelms et al.). IL-4 drives immunoglobulin class switching in B cells (to IgE, IgG4), mast cell hyperplasia, mucus production, and the differentiation of naïve T cells into T helper type 2 (Th2) cells, which produce IL-4, IL-5, IL-10, and IL-13 (Bao et al.; Olpihant et al.; Nelms et al.). In addition to Th2 T cells, IL-4 is produced by CD4+ NK T cells, γ/δ T cells, activated basophils, eosinophils, and mast cells. IL-4 consists of 130 amino acids with a predicted molecular weight of 15.1 kDa. Human IL-4 does not cross-react with mouse cells (Park et al.). This product is animal component-free.

Supplier: STEMCELL Technologies

Interleukin 10 (IL-10) is the founding member of the IL-10 family of class II cytokines. All of the IL-10 cytokine family members have a four-helix bundle consisting of α-helical folds. Upon binding to its receptor, IL-10 activates signaling through JAK1 and STAT3. It is produced by dendritic cells, macrophages, and CD4+ T regulatory cells, as well as mast cells, NK cells, neutrophils, and regulatory B cells, under specific stimulating conditions (Saraiva and O'Garra). IL-10 can inhibit the activation of certain immune cells while it promotes the function of B cells, and facilitate healing process. Specifically, this cytokine is important for the function of T regulatory cells as it is a potent suppressor of effector T cell proliferation and cytokine production. Also, IL-10 produced by a subset of macrophages inhibits activation and production of pro-inflammatory cytokines by neighboring macrophages, thus allowing a level of self-regulation. IL-10 enhances B cell proliferation, immunoglobulin secretion, and class II MHC expression (Ouyang et al.).

Supplier: STEMCELL Technologies

Tumor necrosis factor-alpha (TNF-α) is a pro-inflammatory cytokine that activates NF-κB, MAPK, and PI3K/AKT pathways. Activated T cells and macrophages are the primary producers of TNF-α in response to inflammation and infectious conditions. Many other cell types have been shown to produce TNF-α, among them B cells, NK cells, mast cells, neutrophils, dendritic cells, microglia, endothelial cells, smooth muscle cells, cardiomyocytes, and fibroblasts. TNF-α has cytotoxic effects on cancerous cells by stimulating anti-tumor immunosuppressive responses. TNF-α stimulates expression of E- and P-selectins, thus facilitating adhesion of neutrophils, monocytes, and memory T cells to activated platelets and endothelial cells (Zelová and Hošek). Other effects of TNF-α include vasodilatation and edema formation. In vitro studies of adult rat neural progenitor cells (NPCs) demonstrate that TNF-α reduces neurogenesis in dentate gyrus-derived NPCs, and promotes astrogliogenesis in subventricular zone-derived NPCs (Borsini et al.).

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Leptin is a protein produced from the ob gene or lep gene, and acts as both a hormone involved in metabolic function as well as a proinflammatory cytokine by inducing Th1 immune responses (Dunn et al.; La Cava; Newman and Gonzalez-Perez). Leptin is a member of the gp130 family of cytokines and is known to be correlated with obesity (Dixit et al.; Dunn et al.). Leptin can both promote osteogenesis via osteoblast receptors and inhibit it through its actions on the hypothalamus (Figenschau et al.). It is a small, non-glycosylated protein with a highly conserved sequence between species. Leptin binds to the leptin receptor OB-R, which exists in six isoforms in humans and can activate various Janus kinase (JAK) and downstream pathways (Dunn et al.; Münzberg and Morrison; Newman and Gonzalez-Perez). For example, the binding of leptin to LepRb receptor activates JAK2, which leads to the phosphorylation of both JAK2 and the LepRb receptor, with three separate residues on the receptor triggering signaling pathways for SHP-2, STAT5, and STAT3 (Dunn et al.; Münzberg and Morrison). In addition to its effects on mature immune cells, other studies have suggested impacts on other cell types, with activities such as inducing cell proliferation and morphological differentiation in hematopoietic cell lines, chondrocytes, and hepatic cells (Figenschau et al.; Gainsford et al.; Santos-Alvarez et al.; Wang et al.).

Supplier: STEMCELL Technologies

The CMV (pp65) peptide pool is a lyophilised mixture of 138 peptides from the 65 kDa phosphoprotein (pp65) of human cytomegalovirus (CMV; strain AD169). pp65 has been shown to counteract the induction of interferon response by preventing the activation of interferon response factor 3 (IRF-3). pp65 is also important in inducing transcription of viral immediate-early promoter. The pool consists of 15-mer peptides with 11-amino-acid overlaps that cover amino acids 1 to 561 on pp65.

Supplier: STEMCELL Technologies

Galectin-1 (Gal1) was the first characterized member of the galectin family of galactosidase-binding proteins, with over 15 mammalian galectins identified (Camby et al.; Salatino et al.). Gal1 comes in two forms: the oxidized monomer that acts as a cytokine, and the reduced dimer that acts as a lectin (Gaudet et al.). This product is in the dimer form. This cytokine is expressed in many tissues and has an immunosuppressive role in affecting T cell homeostasis by various mechanisms such as regulating apoptosis, cytokine secretion, cell adhesion, cell proliferation, and other effects (Camby et al.; Garín et al.; Gaudet et al.; Salatino et al.). In addition, Gal1 is thought to also play a role in axonal regeneration after injuries (Camby et al.; Garín et al.; Gaudet et al.; Salatino et al.). There are several therapeutic applications suggested for Gal1; overexpression has been suggested as a therapy for autoimmune and inflammatory diseases and enhancing axonal regeneration in injured nerves (Camby et al.; Gaudet et al.). In contrast, inhibition of Gal1 has been suggested to prevent tumor metastasis and cancer progression, as it may aid in cell adhesion, migration, and immune escape of cancer cells (Camby et al.).

Supplier: STEMCELL Technologies

The EBV (EBNA-1) Peptide pool is a lyophilised mixture of 158 peptides from Epstein-Barr nuclear antigen 1 (EBNA-1) of Epstein-Barr virus (EBV; strain B95-8). EBNA-1 plays a critical role in the stable latent infection by EBV and may contribute to the survival of EBV-infected cells through its interaction with ubiquitin carboxyl-terminal hydrolase 7 (USP7). The pool consists of 15-mer peptides with 11-amino-acid overlaps that cover amino acids 1 to 641 on EBNA-1.

Supplier: STEMCELL Technologies

Stimulating T cells with Candida (MP65) peptide pool releases downstream cytokines and upregulates activation markers, enabling antigen-specific T cells to be detected or isolated for analysis. Candida peptide pool is a lyophilised mixture of 92 peptides from the mannoprotein MP65 of Candida albicans (yeast), and consists of 15-mer peptides with 11-amino-acid overlaps that cover amino acids 1 to 379 on MP65. MP65 contributes to cell wall integrity and epithelia adherence (Sandini et al.), and is a potent T cell immunogen (Gomez et al.). Viral peptide pools are useful for a broad range of applications, including vaccine development, immunological research, and diagnostic assay development.

Supplier: STEMCELL Technologies

The platelet-derived growth factor (PDGF) family has five heparin-binding members that assemble into four homodimers (PDGF-AA, PDGF-BB, PDGF-CC, and PDGF-DD) and one heterodimer (PDGF-AB; Li and Eriksson). PDGF signals through the receptor tyrosine kinases PDGFRα and PDGFRβ. It has been shown that PDGF-induced migration involves signaling pathways involving MEK/ERK, EGFR, Src and PI3K/AKT (Kim et al.). PDGF is a potent mitogen for cells of mesenchymal origin such as fibroblasts and vascular smooth muscle cells. PDGF has been implicated in pathogenesis of atherosclerosis, glomerulonephritis, cancer, and in the contraction of vascular smooth muscle cells of rat aortic tissues (Fretto et al.; Sachinidis et al.). PDGF-CC is secreted as a latent growth factor and requires activation by proteolytic processing (Li and Eriksson). PDGF-CC binds to PDGFRα homodimers and PDGFRαβ heterodimers, but not to PDGFRβ homodimers (Li and Eriksson). PDGF-CC is an angiogenic factor that stimulates coronary artery smooth muscle cell proliferation and plays a role in cardiovascular development (Gilbertson et al.). PDGF-CC is also expressed in many tumors and plays a role in tumorigenesis (Zwerner and May).

Supplier: STEMCELL Technologies

Ciliary neurotrophic factor (CNTF) is a neurotrophic factor that belongs to the four-helix bundle cytokine family and is structurally related to interleukin 6 (IL-6), interleukin 11 (IL-11), leukemia inhibitory factor (LIF), and oncostatin M (OSM). CNTF binds to its receptor CNFTRα and induces formation of a heterodimer of the signal-transducing IL-6 receptor gp130 and LIF receptor (LIFR)-β, which triggers JAK/STAT, ERK, and the PI3K signaling cascades (Schuster et al.). CNTF plays an important role in neurogenesis and the differentiation of neural stem cells and has been suggested to possess a therapeutic role in treating neurological disorders (Ding et al.; Oppenheim et al.). CNTF has also been shown to protect rod photoreceptors from light-induced damage and to have therapeutic effects on retinal degenerative diseases caused by genetic defect or damage induced by toxins, autoantibodies, or strong light (Pernet et al.; Rhee et al.). Another therapeutic role of CNTF has been reported in protecting oligodendrocytes from death induced by apoptosis (Louis et al.). Additionally, CNTF is commonly used to differentiate human pluripotent stem cell (hPSC)-derived neural progenitor cells into astrocytes (Krencik and Zhang).

Supplier: STEMCELL Technologies

Granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes the proliferation and differentiation of hematopoietic progenitor cells and the generation of neutrophils, eosinophils, and macrophages. In synergy with other cytokines such as stem cell factor, IL-3, erythropoietin, and thrombopoietin, it also stimulates erythroid and megakaryocyte progenitor cells (Barreda et al.). GM-CSF is produced by multiple cell types, including stromal cells, Paneth cells, macrophages, dendritic cells (DCs), endothelial cells, smooth muscle cells, fibroblasts, chondrocytes, and Th1 and Th17 T cells (Francisco-Cruz et al.). The receptor for GM-CSF (GM-CSFR) is composed of two subunits: the cytokine-specific α subunit (GMRα; CD116) and the common subunit βc (CD131) shared with IL-3 and IL-5 receptors (Broughton et al.). GM-CSFR is expressed on hematopoietic cells, including progenitor cells and immune cells, as well as non-hematopoietic cells. Recombinant human GM-CSF (rhGM-CSF) promotes the production of myeloid cells of the granulocytic (neutrophils, eosinophils, and basophils) and monocytic lineages in vivo. It has been tested for mobilisation of hematopoietic progenitor cells and used to treat chemotherapy-induced neutropenia in patients. GM-CSF is able to stimulate the development of DCs that ingest, process, and present antigens to the immune system (Francisco-Cruz et al.).

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Interleukin 11 (IL-11) is a pleiotropic cytokine with effects on various tissues including the bone marrow, brain, and intestinal mucosa (Du and amp; Williams). It belongs to the IL-6 family of cytokines that share a common signal transducer, gp130. Culture of mouse bone marrow cells with IL-11 in combination with IL-3, IL-6, and stem cell factor induces significant expansion and proliferation of colony-forming cells in vitro (Peters et al.). In addition, in combination with IL-3, IL-11 significantly enhances the growth of megakaryocytic colonies in vitro, suggesting its role in augmenting mouse megakaryopoiesis (Yonemura et al.). IL-11 is expressed in a wide range of normal adult mouse tissues, including the central nervous system, thymus, lung, and bone. The mouse IL-11 cDNA was cloned using an expression library generated from the lipopolysaccharide-induced mouse fetal thymic cell line, T2 (Morris et al.). The binding of IL-11 to its receptor induces heterodimerization with the gp130 subunit and activation of JAK tyrosine kinases. IL-11 also plays a role in cancer progression by inducing the proliferation of epithelial cancer cells and the survival of metastatic cells at distant organs. Recently, IL-11 has gained interest for its role in the pathogenesis of diseases in dysregulated mucosal homeostasis associated with STAT3 upregulation, including gastrointestinal cancers (Putoczki et al.).

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The principal physiological regulator of erythropoiesis, Erythropoietin (EPO) is a glycoprotein growth factor that is produced primarily in the kidney in response to hypoxia or anemia. EPO promotes erythropoiesis by binding to a homodimeric cell surface receptor that activates JAK2/STAT5, PI3K/AKT, and MAPK pathways, and stimulates the proliferation and differentiation of erythroid progenitor cells (Jelkmann. Transfus Med Hemother, 2013; Kuhrt and Wojchowski. Blood, 2015).

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Noggin binds to and antagonizes bone morphogenetic protein (BMP) ligands of the transforming growth factor beta (TGF-β) family. Noggin supports maintenance of undifferentiated human embryonic stem cells in vitro, and can be used to prevent spontaneous differentiation in the short term (Chaturvedi et al.). Noggin is essential for development of structures derived from ectoderm embryonic somite, skeletal patterning, and neurogenesis in vivo. It also influences chondrogenesis, osteogenesis, and joint formation (Krause et al.), and promotes dopaminergic differentiation of embryonic stem cells and subsequent survival of dopamine neurons (Chiba et al.).

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Epidermal growth factor (EGF) is characterized by high affinity binding to various EGF receptors (EGFRs) and the production of mitogenic responses (Carpenter and Cohen). EGF promotes EGFR dimerization, resulting in activation of downstream pathways including PI3K, ERK1/2, JAK/STAT, β-catenin, and calcium signaling. EGF is secreted by the gut-associated salivary and Brunner’s glands, is found in a variety of body fluids, and stimulates cell proliferation and differentiation in rodent and neonatal human intestine (Wright et al.). Central nervous system stem cells also proliferate in response to the EGF stimulus (Reynolds and Weiss).

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SARS-CoV-2 Recombinant Spike Protein, aa16-685 is expressed in HEK293 cells and is one of four structural proteins encoded by the SARS-CoV-2 genome. The Spike Protein plays a key role in attachment to host cells, allowing invasion through clathrin-mediated endocytosis. The Spike Protein can be cleaved by host cell proteases after aa685 to yield the N-terminal S1 subunit and C-terminal S2 region. The S1 subunit is responsible for interacting with the host cell receptor (angiotensin-converting enzyme II) through a receptor-binding domain that is highly conserved with SARS-CoV. The S1 subunit has two conformations: a ‘down’ conformation in which the receptor is inaccessible, and an ‘up’ conformation in which the receptor is accessible. These conformational changes are key for monoclonal antibody drugs and vaccine development. SARS-CoV-2 Recombinant Spike Protein contains a polyhistidine tag at the amino terminus; it also contains a FLAG tag at the carboxy terminus.

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Vascular endothelial growth factor (VEGF-121) is a naturally-occurring VEGF-A splice variant involved in embryonic vasculogenesis and angiogenesis. VEGF binds to VEGFR-1 and VEGFR-2, and activates Raf/MEK/ERK and PI3K/AKT pathways. VEGF-121 is released as a freely diffusible protein by a variety of normal and transformed cells. It plays an important role in neurogenesis both in vitro and in vivo (Storkebaum et al.). It has neurotrophic effects on neurons of the central nervous system and promotes growth and survival of dopaminergic neurons and astrocytes. VEGF also promotes growth and survival of vascular endothelial cells, monocyte chemotaxis, and colony formation by granulocyte-macrophage progenitor cells (Ferrara et al.).

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Amphiregulin is a member of the epidermal growth factor (EGF) family. It binds to several receptors including EGFR/ErbB1, HER2/ErbB2, HER3/ErbB3, and HER4/ErbB4, which activates Ras/Raf/MAPK and PI3K/AKT pathways. This results in cell proliferation, apoptosis resistance, and invasive behaviour (Normanno et al.). The expression of amphiregulin is induced by tissue injury and inflammation. Amphiregulin promotes mammary development, trophoblast growth, lung and kidney branching morphogenesis, and keratinocyte proliferation. It stimulates the growth of most cell types, including normal and transformed mammary epithelial cells, and malignant cells of the colon, prostate, cervix, and pancreas (Berasain and Avila).

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Insulin-like growth factor 1 (IGF-I) is a polypeptide that belongs to the family of insulin-like growth factors that are similar in molecular structure to proinsulin. IGF-I binds to the IGF-I receptor and is a potent activator of the PI3K/AKT pathway and also activates ERK1/2 signaling. IGF-I is required for embryonic development, and it is produced mainly in the liver in response to a hepatocyte growth hormone. In the absence of insulin, IGF-I is necessary for the maintenance of human pluripotent stem cells (Wang et al.). Together with IL-3, IGF-I stimulates differentiation and proliferation of myeloid cells and has been shown to regulate lymphopoiesis by stimulating proliferation and differentiation of T and B cells in lymphoid organs (Heemskerk et al.).