TSC1 and obesity due to melanocortin 4 receptor deficiency: The TSC1 gene regulates mammalian target of rapamycin signaling partly through perception of upstream stimuli such as intracellular and extracellular growth factors, environmental changes, energies, and nutrients; however, further studies evaluating the importance of TSC1 methylation status in obesity are required (Leng et al., 2018).