CDX2 and non-small cell lung carcinoma: The results obtained in this systematic review suggest that the rs10741657, rs4646536, rs7041, rs6068816, BsmI, Cdx-2, FokI, ApaI, and TaqI SNPs in genes related to synthesis (CYP2R1, CYP27B1), transport (GC), metabolism (CYP24A1), and binding to the vitamin D receptor (VDR) could be considered predictive biomarkers of OS and PFS in patients with NSCLC.