,2 Lynch syndrome is caused by pathogenic germline variants (PV) in DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, PMS2 or by a deletion of the 3’ end of EpCAM (TACSTD1).3, 4, 5, 6, 7 Besides an increased risk of up to 57.1% to develop colorectal cancer (CRC; cumulative incidence at age 75 for MLH1 up to 57.1%; MSH2 up to 51.4%; MSH6 up to 20.3%; PMS2 up to 10.4%), female carriers are also at high risk to develop gynaecological malignancies, such as endometrial cancer and cancer in the ovaries (OC).8 The gene discussed is PMS2; the disease is colorectal cancer.