We studied 18 genes known to be important in CRC susceptibility (APC, AXIN2, BMP4, BMPR1A, CHEK2, MLH1, MLH3, MSH2, MSH3, MSH6, MUTYH, PMS1, PTEN, SMAD4, STK11, STK11IP, TGFBR2, and TP53) and 18 genes suspected to play a role in CRC susceptibility (AXIN1, BLM, BUB1, CDH1, CDKN1B, CDKN2A, CTNNB1, FLCN, GALNT12, NUDT1, OGG1, PALB2, REQL5, SMAD1, SMAD2, SMAD3, TGFB1, and TGFBR1). The gene discussed is MLH3; the disease is colorectal carcinoma.