MLH1 and neoplasm: Significant associations were observed between MLH1 promoter methylation and gender (pooled OR = 1.641, 95% CI: 1.215–2.215; P = 0.001), tumor location (pooled OR = 3.804, 95% CI: 2.715–5.329; P<0.001), tumor differentiation (pooled OR = 2.131, 95% CI: 1.464–3.102; P<0.001), MSI (OR: 27.096, 95% CI: 13.717–53.526; P<0.001).