Mediate calcium phosphate clearance and prevent ectopic calcification with fetuin A, a plasma glycoprotein that forms soluble complexes with calcium and phosphate (Heiss et al.; Price and Lin). Belonging to the cystatin superfamily of cysteine protease inhibitors (Brown and Dziegielewska), fetuin A has also been shown to play a role in lipid transport, acting as a carrier (Kumbla et al.). In cell-based assays, it has been suggested that fetuin A protects against lethal systemic infection through the inhibition of high mobility group box 1 (HMGB1) protein accumulation and release (Li et al.). Fetuin A acts as a natural antagonist against specific TGF-β and BMP signaling proteins, blocking osteogenic differentiation of rat bone marrow cells (Demetriou et al.). This protein contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, fetuin A from STEMCELL comes lyophilised with ≥94% purity, and endotoxin levels are verified to be ≤1.0 EU/μg protein.