BRCA2 and breast cancer: Using BRCA2-d in the set of HMF breast cancer tumours (n = 645) as an example, we observed biallelic LOF events in 17 (2.6%; 14 germline, 3 somatic) tumours and monoallelic LOF events in 7 (1.1%; 4 germline, 3 somatic) tumours (Supplementary file 1g).