Rapamycin [mammalian target of rapamycin (mTOR)] is mainly regulated by the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) pathway, and is over-activated in both sporadic and hereditary brain tumors, related to cell growth, differentiation and tumorigenesis (36) (Figure 2). The gene discussed is MTOR; the disease is brain neoplasm.