CYP24A1 and rectal cancer: According to the results of subgroup analysis of the cancer site, the hypermethylation of CYP24A1 was inversely associated with the risk of both colon and rectal cancer, with aORs of 0.18 (95% CI, 0.08–0.42; P < 0.001) and 0.20 (95% CI, 0.08–0.49; P < 0.001), respectively (Pheterogeneity = 0.86) (Fig. 3).