MLH1 and colorectal cancer: Patients with positive MLH1/ MSH2 more frequently suffered from right-side colon, with 1-3 lymph nodes metastasis, with mucus, positive surgical margin (P<0.05), but with no evidence related with age, gender, tumor size, differentiation and TNM stage.Patients with negative MLH1/MSH2 showed significantly better OS than positive one(P<0.05).Univariate and multivariate analysis demonstrated that the independent predictive factors of colorectal cancer were TNM stage, lymph nodes metastasis, mucus, surgical margin and MLHl/MSH2 status(P<0.05).