IRS1 and colorectal carcinoma: For IRS1 rs1801278G>A, pooled results based on 5 studies (comprising 5,371 cases and 6,255 controls) revealed a significant association between the polymorphism and an increased CRC risk in some of the comparisons studied (AA, OR = 0.75, 95% CI 0.17-3.33, P = 0.712; GA, OR = 0.74, 95% CI 0.58-0.94, P = 0.016; GG, OR = 1.06, 95% CI 0.82-1.37, P = 0.644) (Figure 3).