Pan-cancer, significantly higher HRDsum scores were detected in tumors with alterations in 24 genes including BRCA1, BRCA2, RAD51B, and RAD51C. Within specific cancer types, significantly higher HRDsum scores were detected in BRCA1-mutated OV and BRCA; in BRCA2-mutated OV, BRCA, PRAD, BLCA, and GBM; in PTEN-mutated OV and PRAD; in ATM-mutated THCA and LUAD; in BAP1-mutated KIRC and KIRP and in others. Here, BRCA1 is linked to cancer.