The percentage of MMR-deficient breast carcinomas was lower among MSH6 mutation carriers (2/6, 33% by IHC and 0/7 by MSI analysis) compared to carriers of MSH2 (3/3, 100% and 3/5, 60%, respectively) or MLH1 mutation (8/11, 73% and 5/11, 45%, respectively) (statistically not significant). The gene discussed is MSH2; the disease is breast carcinoma.