ABCA1 and atherosclerosis: Animal models of atherosclerosis have yielded conflicting results on the impact of LCAT deficiency and overexpression.15,16 Serum from LCAT-deficient subjects exhibits elevated ABCA1-dependent cellular cholesterol efflux although efflux by ABCG1 and SR-B1 is impaired, suggesting that cholesterol efflux by the ABCA1 pathway might explain why those subjects are not at high risk for CVD.17