(A) BRCA1/2 mutations (grouped) with a germline (gBRCA1/2) or somatic (sBRCA1/2) prediction were evaluated for biallelic/monoallelic status for all cancers, BRCA1/2-associated cancers (as a group and as individual cancer types), and non–BRCA1/2-associated cancers (see Data Supplement). Biallelic fraction was assessed for (B) gBRCA1/2- and (C) sBRCA1/2-mutated cases. Numbers on the x-axis indicate number of cases assessed for biallelic status gBRCA1 or gBRCA2. CUP, cancer of unknown primary; HNSCC, head and neck squamous cell carcinoma; NSCLC, non–small-cell lung cancer; SCC, squamous cell carcinoma; SCLC, small-cell lung cancer; UC, urothelial cancer.