PIK3CA and breast cancer: Natural products and derived bioactive compounds showed anticancer activities against BC by interacting with estrogen receptors, protein kinases, and the downstream regulation of signaling pathways (such as Notch, NF-κB- PI3K/Akt/mTOR, MAPK/ERK, and MDM2 pathways) by inducing apoptosis and cell death [23,33,34,35,36].