Alpha-[11C]methyl-L-tryptophan ([11C]AMT) PET shows increased tracer uptake interictally in epileptogenic tubers only of patients with tuberous sclerosis (TSC1 and TSC2) and in dysplastic cortex with an excellent agreement in seizure focus lateralization between ictal scalp EEG and [11C]AMT. This evidence concerns the gene TSC1 and tuberous sclerosis.