In both cohorts, PIK3CA mutations were more prevalent in BRCA2mut tumors versus tumors harboring BRCA1mut (Table 3), with differences in mutation incidence reflecting tumor subtype differences: 5/6 patients with PIK3CA mutations had tBRCA2mut hormone-receptor positive (HR+) disease, while the remaining patient had tBRCA1mut triple-negative breast cancer (TNBC) (data not shown). This evidence concerns the gene PIK3CA and triple-negative breast carcinoma.