NCOA3 and breast cancer: However, SRC-3 also affects the growth of hormone-independent breast cancer and SRC-3 levels are limiting for IGF-1-, EGF-, and heregulin-stimulated biological responses in breast cancer cells, and consequently, the PI3 K/Akt/mTOR and other EGFR/HER2 signaling pathways are controlled by changes in SRC-3 protein levels [280].