The expression of hepatic CYP8B1 is regulated exactly as HSDL2: It is (i) increased upon fasting (59, 60), (ii) activated by PPARα agonists (59, 62), (iii) repressed by insulin (63), and (iv) elevated in type 1 diabetes (63). This evidence concerns the gene HSDL2 and type 1 diabetes mellitus.