PIK3CA and breast cancer: For NSCLC cells with high Akt expression, the use of PI3K/Akt signaling pathway inhibitors increases their cell apoptosis induced by chemotherapy and reduces their resistance to chemotherapy; furthermore, inhibition of the PI3K/Akt signaling pathway effectively improves drug-induced lung cancer cell apoptosis.142 Moreover, members of the PI3K/Akt signaling pathway play an important role in antiestrogen resistance in breast cancer.143