AKT1 and breast cancer: Once activated, AKT can phosphorylate multiple substrates and downstream effectors, such as mTOR family, caspase family, cell cycle protein family and nuclear factor-κB (NF-κB), which contribute collectively to promote cell proliferation, survival, metastasis and chemoresistance.10, 11, 12 As this signaling cascade has a central role in human breast cancer, development of novel strategies to overcome resistance and eliminate CSC by targeting the PI3K/AKT pathway is apparently warranted.13