Abstract: Phosphatidylinositol-3-kinase (PI3K)，AKT ,TSC1/2, and the mammalian target of rapamycin (mTOR) signaling cascade involves in many cellular processes including apoptosis, growth, proliferation and differentiation, This pathway has been found to be most frequently altered in human tumors. As tumor is a poorly differentiated disease, this review will examine the role of the PI3K-AKT signal pathway in cell differentiation and tumor development.