A member of the pentraxin family of proteins, C-reactive protein (CRP) plays important roles in host defenses, including regulating complement activation in vivo (Sjoberg et al.), decreasing nitric oxide production, and inhibiting angiogenesis in vitro (Verma et al., 2002). At specific concentrations, CRP directly inhibits endothelial progenitor cell (EPC) differentiation, survival, and function, and is thus implicated in the development of cardiovascular diseases (Verma et al., 2004). CRP is primarily synthesized by liver hepatocytes, but also by other immune cells, such as macrophages and lymphocytes (Sproston & Ashworth). The expression of this acute-phase protein is induced by IL-6 and IL-1 secretion of macrophages and T-cells during inflammation. For consistency and reproducibility across your applications, C-reactive protein from STEMCELL comes lyophilized with ≥ 87% purity, and endotoxin levels are verified to be ≤ 1.0 EU/μg protein.