Tumor-only sequencing was unable to detect 13.2% (95% CI 8.9% to 19.1%; 22/167), 8.1% (95% CI 4.5% to 14.3%; 10/123), 6.8% (95% CI 3.5% to 12.8%; 8/118) and 5.6% (95% CI 2.8% to 11.2%; 7/124) of the P/LP germline variants affecting HDR or DDR genes in breast, pancreatic, prostate and ovarian cancers, respectively, and 14.1% (95% CI 8.3% to 23.1%; 12/85) and 9.7% (95% CI 3.4% to 24.9%; 3/31) of the P/LP germline variants in MMR genes in colorectal and endometrial cancers, respectively (Supplementary Table S5, available at https://doi.org/10.1016/j.annonc.2022.01.006). This evidence concerns the gene MRC1 and ovarian carcinoma.