TSC2 and tuberous sclerosis: Tuberous sclerosis complex (TSC) is a rare genetic disorder that is associated with pathogenic TSC1 or TSC2 gene variants, identified in 75%–90% of individuals with TSC, that have been shown to cause upregulation of the mechanistic target of rapamycin (mTOR), which in turn leads to formation of hamartomas in multiple organ systems, including the brain, heart, skin, eyes, kidneys, lungs, and liver [1,2].