Out of the 1552 tumors with HRDsum ≥ 42 in the pan-cancer analysis, 9% and 3% had BA and MA deleterious BRCA1/2 alterations (class H1a), 14% and 13% had BA and MA deleterious alterations in other HRR genes (class H1b) and 5% were BRCA1-hypermethylated (Supplementary Fig. 10). Here, BRCA1 is linked to cancer.