APOE and atherosclerosis: On the other hand, complete (whole-body) knockout of Scarb1 increases atherosclerosis in apoE−/− mice (Scarb1−/−, apoE−/−) as a result of impaired RCT [29], and humans who are homozygous for a rare loss-of-function mutation of Scarb1 are 1.8 times more likely to develop coronary heart disease [30].