With one exception (case MSH6_7 with insufficient DNA), we Sanger sequenced the mutational hotspots exons in POLD1/E (see Section 4) in normal tissues from all our cases suspected of having MSH2 or MSH6 mutation, and in available tumor tissues as well when relevant (a separate analysis was necessary since the CCP panel did not include the POLD1/E genes). The gene discussed is POLD1; the disease is neoplasm.