Truncation of MLH1 at amino acid 749–750 impairs the ability of Mlh1 to act in error correction, checkpoint signaling and Pms2 interaction and stabilization...Germline MLH1 mutations are associated with Lynch syndrome, which is manifested by increased risk of a number of cancers, especially colorectal carcinoma. The gene discussed is PMS2; the disease is colorectal carcinoma.