Cytochrome P450 26B1 is a protein that in humans is encoded by the CYP26B1gene.
This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases that catalyze many reactions involved in drug metabolism and the synthesis of cholesterol, steroids and other lipids. The enzyme encoded by this gene is involved in the specific inactivation of all-trans-retinoic acid to hydroxylated forms, such as 4-oxo-, 4-OH-, and 18-OH-all-trans-retinoic acid.
CYP26B1 has been shown to be over-expressed in colorectal cancer cells compared to normal colonic epithelium. CYP26B1 expression was also independently prognostic in patients with colorectal cancer and strong expression was associated with a poorer outcome.
Rat E, Billaut-Laden I, Allorge D, et al. (2006). "Evidence for a functional genetic polymorphism of the human retinoic acid-metabolizing enzyme CYP26A1, an enzyme that may be involved in spina bifida". Birth Defects Res. Part a Clin. Mol. Teratol.76 (6): 491–8. doi:10.1002/bdra.20275. PMID16933217.