Mutation analysis using cBioportal database indicated that alteration of SNX family exerted great impact on MSI occurrence in GC, and that those with SNX alteration were on a higher trend to undergo tumor-suppressing gene mutation, such as TP53, ARID1A, and MLH1.Clinical information from TCGA database and several SNXs shown as independent risk factors was employed to construct a multivariate cox regression model visualized as nomogram for OS prediction and risk classification. The gene discussed is MLH1; the disease is neoplasm.