The results indicated that TCF7L2 polymorphism might not be associated with cancer risk under co-dominant model (Homogeneous model: OR = 1.07, 95%CI = 0.95–1.21, I2 = 61.4%, p for heterogeneity<0.001, Figure 2; Heterogeneous model: OR = 1.04, 95%CI = 0.97–1.12, I2 = 58.1%, p for heterogeneity = 0.001, Figure 3). This evidence concerns the gene TCF7L2 and cancer.