In the autosomal dominant disorder hereditary nonpolyposis colorectal cancer (HNPCC), the most common hereditary predisposition for the development of colorectal cancer, TBRII gene contains a 10-base pair polyadenine repeat microsatellite sequence, and up to 80% of colon cancer patients with HNPCC present this mutated form of TBRII [21]. The gene discussed is TGFBR2; the disease is hereditary nonpolyposis colon cancer.