MRC1 and Lynch syndrome: After immunohistochemistry and methylation analysis, 24 patients were triaged as potential Lynch syndrome-associated, showing loss of expression of the MMR proteins PMS2 only (N = 4), MSH2/MSH6 (N = 7), MSH6 only (N = 11), MLH1/MSH2 (N = 1), and MLH1/PMS2 without MLH1 promoter hypermethylation (N = 1).