Downregulation of PTEN and activation of Akt and mTOR have been shown to be critical for proliferation and survival of CSCs and specifically, breast cancer stem cells [34], and an active PI3K/Akt/mTOR signalling axis is required for the maintenance of the undifferentiated properties of ESCs [35] and iPS cells [36]. The gene discussed is AKT1; the disease is breast carcinoma.