The ABCA1 molecule is a primary gatekeeper for regulating the intracellular transport of cholesterol. It belongs to a larger related multifamily of cAMP-dependent anion transporter cell membrane molecules. These key proteins are responsible for trafficking the reverse efflux of cholesterol from cells into peripheral tissues using the apolipoprotein A-1 (apo) carrier. In particular, the ABCA1 molecule exhibits a diverse expression profile and is found most highly expressed in macrophages.