CYP7A1 and familial hypercholesterolemia: Of note, a mild hypercholesterolemia has already been observed due to Keap1 deletion in WT mice and was attributed to a reduced expression of the Cyp7a1 (cytochrome P450 family 7 subfamily A member 1) gene, which encodes for an enzyme involved in the biotransformation of cholesterol into bile acids [33].