“…The black line with an arrow represents the activation process and the red line with a rectangular bar at the end represents the suppression process. (Ballif et al, 2005;Campos et al, 2016;Corradetti, Inoki, Bardeesy, DePinho, & Guan, 2004;Ellisen, 2005;Gao et al, 2015;Hoxhaj et al, 2017;Huang, Wu, Wu, & Manning, 2009;Inoki et al, 2006;Inoki, Li, Zhu, Wu, & Guan, 2002;Natarajan, Trivedi-Vyas, & Wairkar, 2013;Sofer, Lei, Johannessen, & Ellisen, 2005;Zhang et al, 2003) variants have been sought in DNA from blood. However, when the analysis is negative and the patient has a clinical diagnosis but a mild phenotype, clinicians should consider mosaicism and may try to analyze a different tissue, such as buccal smear, skin biopsy of a facial angiofibroma or of a hypomelanotic macule, brain or renal tissue if surgery is going to be performed.…”