MTOR and tuberous sclerosis: The protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway is downstream of PI3K and plays a vital role in regulating cell proliferation, apoptosis, and metabolism.[7] mTOR activity is altered in various nervous system diseases, including brain tumors, tuberous sclerosis, cortical dysplasias, and neurodegenerative disorders such as Alzheimer disease, Parkinson disease, and Huntington disease.[8] Therefore, inhibiting mTOR activity may reduce the neurodegenerative changes associated with these diseases.