MSH2 and gastric cancer: To characterize how the immune system restricts metastatic spread across gastric cancer subtypes, we performed experimental metastasis assays using cell lines derived from primary EPO-GEMM tumors representing the GS (MYC-Apc−/−), CIN (MYC-p53−/−) and MSI (MYC-p53−/−-Msh2−/−) subtypes.