MLH1 and cancer: In addition, on the basis of the tumor and matched normal tissues of the patients, we classified the patient characteristics according to five individual gene groups (CDKN2A, hMLH1, MGMT, CSF2, and DIS3L2) and according to those with two or more genes with aberrant methylation, stratified by different variables (sex, age at surgery, cancer stage, progression, all-cause death, progression including death, adjuvant chemotherapy, histological grade, and tumor location).