All 20 colorectal cancer cases with MLH1 hypermethylation (MLH1 hypermethylated-CRC) lost MLH1 expression, whereas the eight colorectal cancer cases with unmethylated MLH1 (non-MLH1 hypermethylated-CRC) expressed MLH1 (Supplementary Table S1), indicating that MLH1 hypermethylation determined by our MSP assay accurately reflects silencing of the MLH1 expression. Here, MLH1 is linked to colorectal cancer.