PIK3CA and breast cancer: Documented breast cancer oncogenes (NOTCH2, ENSA, PIK3CA, CD44, WT1, BCL2L2, AKT2, and TFF3) and tumor suppressors (BRCA2 and PRKCDBP) reside or are in close proximity to some of these significantly amplified/deleted genomic regions, and these alterations potentially contribute to TNBC progression and BrM development.