Apolipoprotein A1 (ApoA1) is the protein fraction of high-density lipoproteins with anti-inflammatory and antioxidant properties that play a critical role in reversing cholesterol transport. The protein, as a component of HDL particles, enables the efflux of fat molecules by accepting fats from within cells (including macrophages within the walls of arteries which have become overloaded with ingested fats from oxidised LDL particles) for transport elsewhere, including back to LDL particles or to the liver for excretion. ApoA1 is often used as a biomarker for the prediction of cardiovascular diseases. Anti-human apolipoprotein A1 antibodies are used in indirect ELISA, for quantitation of the antigen in serum. They are also used for immunoprecipitation, immunohistochemistry, immunoturbidimetry, nephelometry assays and western blotting for highly sensitive qualitative analysis.