USF1 and familial hypercholesterolemia: Despite the fact that the increased hepatic cholesteryl ester load can possibly underlie the exacerbated hypercholesterolemia and associated atherosclerosis susceptibility, the question remains why an exclusive lack of USF1 in bone marrow-derived cells is associated with a higher steatosis degree as we did not detect a change in the hepatic expression of genes involved in cholesterol synthesis and lipoprotein uptake.