MSH2 and colorectal cancer: What is not known if the additional loss of MSH3 function enhances any characteristic of an already MSI-H colorectal cancer which already has full loss of DNA mismatch repair (as in the case of MLH1 hypermethylation, or germline mutation of MLH1 or MSH2, or PMS2, but perhaps could enhance characteristics of germline MSH6 mutation carriers).