In another study, two protein-truncating mutations in the ATM gene were found in two Polish probands with breast cancer without founder mutations in BRCA1, CHEK2 or NBS1. In that study, both patients with ATM mutations also had another truncating mutation, in the PALB2 and XRCC2 genes, respectively [30]. The gene discussed is XRCC2; the disease is breast carcinoma.