Colorectal cancer was diagnosed in 546 individuals (241 women and 305 men) at the following mutated gene–associated rates: MLH1, 61% (249 of 409); MSH2, 50% (239 of 479); MSH6, 33% (43 of 129); and PMS2, 32% (15 of 46) eTable in the Supplement). Here, PMS2 is linked to colorectal cancer.