A cytochrome P450 monooxygenase involved in the metabolism of retinoates (RAs), the active metabolites of vitamin A, and critical signaling molecules in animals (PubMed:14532297). RAs exist as at least four different isomers: all-trans-RA (atRA), 9-cis-RA, 13-cis-RA, and 9,13-dicis-RA, where atRA is considered to be the biologically active isomer, although 9-cis-RA and 13-cis-RA also have activity (Probable). Catalyzes the oxidation of atRA primarily at C-4 (PubMed:14532297). Oxidation of atRA limits its biological activity and initiates a degradative process leading to its eventual elimination, thereby contributes to the regulation of atRA homeostasis and signaling (Probable). Able to metabolize other RAs such as 9-cis with high efficiency (PubMed:14532297). Can oxidize all-trans-13,14- dihydroretinoate (DRA) to metabolites which could include all-trans-4- oxo-DRA, all-trans-4-hydroxy-DRA, all-trans-5,8-epoxy-DRA, and all- trans-18-hydroxy-DRA (By similarity). Shares sequence similarity with other CYP26 family members, but has higher affinity to 9-cis-RA and is much less sensitive to the inhibitory effects of ketoconazole (PubMed:14532297). In cooperation with Cyp26a1, contributes to the CNS patterning and the development of regions of higher visual acuity (By similarity). {ECO:0000250|UniProtKB:B2RXA7, ECO:0000269|PubMed:14532297, ECO:0000305|PubMed:14532297}. This is the function of ENSG00000187553 (CYP26C1, cytochrome P450 family 26 subfamily C member 1).