The expression of cytochrome P450 family 8 subfamily B member 1 (Cyp8b1), a sterol 12α-hydroxylase, was significantly increased in HF-fed B6 mice, whereas the expression of cytochrome P450 family 27 subfamily A member 1 (Cyp27a1), responsible for non-12 BA synthesis, was significantly decreased in HF-fed B6 mice. Here, CYP8B1 is linked to hydrops fetalis.