The association between HGSOC and BLBC includes at least three independent factors: first, among hereditary forms of breast cancer and ovarian cancer, HGSOC and BLBC are the predominant histological subtypes that develop in BRCA mutation carriers; second, in comparison with other breast and ovarian cancer subtypes, the majority of HGSOCs and BLBCs harbor TP53 mutations and exhibit increased genomic instability; third, both tumors are associated with poor outcome. Here, TP53 is linked to ovarian cancer.