One example for successfully targeted therapy in brain tumors is the recent trial of everolimus for treatment of subependymal giant cell astrocytoma in tuberous sclerosis complex (TSC) patients that characteristically have an overactivated mammalian target of rapamycin (mTOR) kinase due to mutations of TSC1/2 genes and subsequent altered activity of the TSC-gene products. Here, TSC1 is linked to tuberous sclerosis.