In a developing mouse embryo, CYP26B1 is expressed in the distal tip of the forming limb bud with an abundance in the apical ectodermal ridge. In a knockout mouse model, mice manifest with severe limb malformations and die after birth due to respiratory distress. However, if the expression of CYP26B1 is conditionally deleted only prior to E9.5, the limbs are not as severely truncated and more digits are visible. Research suggests that this differenece is attributable to the timing of chrondroblast differentiation.
CYP26B1 has been shown to be over-expressed in colorectal cancer cells compared to normal colonicepithelium. CYP26B1 expression was also independently prognostic in patients with colorectal cancer and strong expression was associated with a poorer outcome.
In a genome-wide study, CCHCR1, TCN2, TNXB, LTA, FASN, and CYP26B1 were identified as loci associated with a risk for developing esophageal squamous cell carcinoma. Of these loci, CYP26B1 exhibited the highest effect size. Moreover, the CYP26B1 locus was found to have two alleles with differing capacities to catabolize all-trans retinoic acid, a chemotherapeutic agent. When the allele with the higher catabolic capacity, rs138478634-GA, was overexpressed, cell proliferation was significantly enhanced in comparison to the other allele, rs138478634-GG. Additionally, research is suggestive of a lifestyle interaction where individuals with the risk allele who partake in smoking or drinking present with an odd-ratio over 2-fold higher than smokers or drinkers without the variant or individuals who refrain.
^Yashiro K, Zhao X, Uehara M, Yamshita K, Nishijima M, Nishino J, Saijoh Y, Sakai Y, Hamada H (2004). "Regulation of retinoic acid distribution is required for proximodistal patterning and outgrowth of the developing mouse limb". Dev. Cell. 6 (3): 411–22. doi:10.1016/s1534-5807(04)00062-0. PMID15030763.
^Dranse HJ, Sampaio AV, Petkovich M, Underhill TM (2011). "Genetic deletion of Cyp26b1 negatively impacts limb skeletogenesis by inhibiting chondrogenesis". J. Cell Sci. 124 (16): 2723–34. doi:10.1242/jcs.084699. PMID21807937.
^Chang J, Zhong R, Tian J, Li J, Zhai K, Ke J, Lou J, Chan W, Zhu B, Shen N, Zhang Y, Gong Y, Yang Y, Zou D, Peng X, Zhang Z, Zhang X, Huang K, Wu T, Wu C, Miao X, Lin D (2018). "Exome-wide analyses identify low-frequency variant in CYP26B1 and additional coding variants associated with esophageal squamous cell carcinoma". Nat. Genet. 50 (3): 338–43. doi:10.1038/s41588-018-0045-8. PMID29379198.
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.