CYP26A1 and neoplasm: Meanwhile, RT-qPCR assays revealed that ALDH6A1, FBP1, HAO2 and PSAT1 were markedly under-expressed in tumor tissues in exceeding 60% cases, and that TYMP, HK3, P4HA3, IL4I1, CYP26A1 and CPT1B were over-expressed in tumor tissues in exceeding 70% cases (Fig. 6A–J).