TSC1 and cancer: Activation of mTORC1, caused by dysregulated upstream signaling through phosphoinositide 3-kinase (PI3K), PTEN, AKT, and TSC1-TSC2, is observed in cancers, hamartoma syndromes such as tuberous sclerosis complex (TSC), and vascular anomalies (Dibble and Cantley, 2015; Krymskaya and Goncharova, 2009; Nathan et al., 2017).