MDM2 and colorectal carcinoma: As shown in Table 3, we did not find a significant association between MDM2 SNP309 polymorphism and CRC risk in overall populations (GG vs. TT: OR = 1.086, 95% CI = 0.773–1.525, P = 0.634; GT vs. TT: OR = 1.217, 95% CI = 0.979–1.512, P= 0.077; GG+ GT vs. TT: OR = 1.176, 95% CI = 0.936–1.478, P= 0.163; GG vs. GT+ TT: OR = 0.959, 95% CI = 0.748–1.230, P=0.743).