MLH1 and malignant colon neoplasm: This post hoc trial analyzed both the microsatellites status by genomic DNA evaluation and the MMR protein status by immunochemistry for MLH1 (MutL homolog 1), mutS homologue 2 (MSH2), mutS homologue 6 (MSH6) and PMS1 homologue 2 (PSM2) proteins, which are the four proteins validated in colon cancer to define MMR status.