CYP7B1 and cystic fibrosis: In addition, compared to that of CF-fed rats, three groups of HMFS-fed rats all exhibited a significant increase in levels of CYP27A1 and CYP7B1 (p < 0.05), with the highest levels also shown in HMFS3-fed rats (23.73 pg/mL and 23.65 pg/mL).