PCNA and Lynch syndrome: In order to confirm that the MLH1 mutation was in fact the disease causing mutation, we further analysed the germline NGS data of two affected and two unaffected Lynch Syndrome family members (Family 2) and looked for common mutations in additional MMR genes: PMS1, PMS2, MSH2, MLH3, MSH6, PCNA, POLD1, EXO1, POLE, EPCAM (Suppl.