MRC1 and cancer: The percent of presumptive predictive test recipients who developed at least one cancer also varied by MMR gene, at 15.7% (n = 161) of MLH1 PV carriers, 14.7% (n = 183) of MSH2 PV carriers, 7.4% (n = 47) of MSH6 PV carriers, and 2.8% (n = 9) of PMS2 PV carriers.