PTEN and brain ischemia: In addition to its normal functions such as control of neuronal migration31, 32 and neuronal size,33, 34 the PTEN protein is involved in pathological processes surrounding neuronal injury such as those associated with brain ischemia, neurological and mental disorders and drug addiction.33, 34, 35, 36, 37, 38, 39 Conditional inactivation of PTEN leads to behavioral abnormalities and neuropathological changes characterized by neuronal hypertrophy.39 Park et al.40 reported that modulation of the PTEN/mTOR pathway promotes axon regeneration in the adult CNS.