Moreover, we found that PIK3CA alterations might not exhibit significant mutual exclusivity or co-occurrence with TP53, ESR1, RB1, CCNE1, CCND1, and BRCA1/2 alterations in HR+/HER2- metastatic breast cancer patients by analysis of the established genomic dataset 76 (Supplementary Table 8). This evidence concerns the gene BRCA1 and breast cancer.