But the studies were in mice[20], to further investigate the effect of SM on the atherosclerosis in human cells, in the present study, we demonstrated that Huh7 cells with higher SMS activity 1) had increased cellular SM and cholesterol content and decreased cholesterol secretion; 2) had increased cellular Apo A-I content and decreased Apo A-I secretion, but normal Apo A-I mRNA expression; and 3) had increased expression of ABCA1, ABCG1 and SR-BI mRNA and protein levels as well as decreased expression of HMG-CoA reductase mRNA. Here, ABCG1 is linked to atherosclerosis.