SCARB1 and atherosclerosis: We have previously demonstrated that HDL-mediated protection of macrophages against cell death involves S1PR1 (30) and SR-B1 (6), and we and others have reported that KO of either SR-B1 in bone marrow-derived cells (48, 65) or S1PR1 in myeloid cells (30), both of which include macrophages, results in increased cell death in atherosclerotic plaques and increased atherosclerosis development.