AHSG (α2-HS glycoprotein), or fetuin-A, is a predominant serum glycoprotein with a molecular weight of 64kDa, and is produced and secreted primarily by hepatic cells. It is highly present in the extracellular matrix (ECM) of the bone.

AHSG (α2-HS glycoprotein) is a multifunctional protein, and acts as an inhibitor of insulin receptor tyrosine kinase. It is involved in insulin resistance by promoting adipose tissue inflammation by functioning as a ligand for Toll-like receptor 4. Therefore, it is linked to the type 2 diabetes. This protein plays a crucial role in the prevention of extracellular calcification. This protein is a candidate plasma biomarker for early hypopharyngeal squamous cell carcinoma (HSCC) diagnosis. It is also a negative acute-phase protein, and its serum levels reduce drastically following surgeries, trauma, burns, and severe inflammation. Studies in Chinese populations show the serum levels of this protein is linked with fatty liver index (FLI), alanine aminotransferance (ALT), and aspartate aminotransferance (AST), which are early indicators of nonalcoholic fatty liver disease (NAFLD).

Lyophilised from 20 mM Tris-HCl, pH 7,5, with 2 mM EDTA.