MSI-H colon cancer cases assessed by (1) on-chip electrophoresis of five satellite markers, (2) DNA sequencing of four exoninc MMR deficiency target mononucleotide repeats, and (3) IHC for four MMR proteins MLH1, MSH2, MSH6 and PMS2. The gene discussed is PMS2; the disease is malignant colon neoplasm.