PIK3CA and breast cancer: Hub genes TNF, STAT3, CTNNB1, and MYC in BC; IL1B, CTNNB1, ESR1, and SRC in PC; CTNNB1, BRCA1, JUN, and KRAS in OC; PIK3CA, PTEN, and ESR1 in EC were found as hypoxic signatures due to radiation.