Apart from an increased risk of colorectal carcinoma, women with HNPCC have a substantial increase in risk of developing endometrial cancer (40-60% life time risk with MLH1 and MSH2 mutations, 71% risk with MSH2 mutations) (Aarnio et al.,1999; Hendriks et al., 2004; Watson et al., 2008). The gene discussed is MSH2; the disease is hereditary nonpolyposis colon cancer.