A recent publication identified differences in carcinogenesis between MMR genes, showing different risks of advanced adenoma (7.7% in MLH1 vs. 17.8% in MSH2 carriers) but a similar proportion of cancer (11.3% in MLH1 vs. 11.4% in MSH2 carriers) and different patterns of CTNNB1 somatic mutations (50% in CRC from MLH1 carriers vs. 7% in MSH2 carriers), suggesting that CRC in MLH1 mutation carriers may evolve more frequently through non-polypous precursor lesions and, therefore, are not prevented by colonoscopies [38]. The gene discussed is CTNNB1; the disease is colorectal carcinoma.