CYP2R1 and colorectal carcinoma: A prospective cohort of 535 CRC patients was genotyped for five vitamin-D-related SNPs, namely GC rs2282679, CYP2R1 rs1993116, DHCR7 rs12785878, CYP24A1 rs6013897, and NADSYN1 rs11234027, and the calculated GRS was tested for its association with overall survival, time to progression and tumor response.