TSC1 and tuberous sclerosis: Clinical features of TSC (Figure 1) include the appearance of low-grade tumors and malformations in the brain, heart, lungs, kidneys, eyes, skin, and bone, and loss of heterozygosity or second-hit mutations of the wild-type TSC1 or TSC2 allele are thought to be responsible for the formation of most of these lesions (Henske et al., 1996; Carsillo et al., 2000; Crino et al., 2010; Qin et al., 2010a, 2011; Tyburczy et al., 2014).