CYP7A1 and coronary atherosclerosis: In addition, PPARα reduces serum cholesterol and LDL levels by regulating cholesterol 7A-hydroxylase, sterol 12a-hydroxylase, increases the level of high-density lipoprotein (HDL), hydrolyzes very low-density lipoprotein (VLDL), and delays the progression of coronary atherosclerosis (42).