SCARB1 and atherosclerosis: DOCK4 stimulates SR-B1 internalization and LDL transport by complexation of SR-B1 and LDL and activation of the RAS-related C3 toxin substrate1 (RAC1), promoting LDL accumulation by macrophages in the arterial wall, the conversion of macrophages to foam cells, and the development of atherosclerosis (64).