Tuberous sclerosis complex (TSC) is a systemic syndrome that is caused by inactivating point mutations in either hamartin (TSC1) or tuberin (TSC2), which leads to sustained activation of the mTORC1 signalling pathway and consequent formation of tumour-like lesions (referred to as hamartomas) in affected organs (Han and Sahin, 2011; Napolioni et al., 2009). The gene discussed is TSC2; the disease is hamartoma.