Recently, available evidence indicates BDNF has a role in the regulation of energy balance as both BDNF and receptors are extensively expressed in the hypothalamus that controls feeding and metabolism activation, and is involved in anorexigenic and orexigenic effects (Di Rosa et al., 2021), suggesting that regulation of the BDNF/TrkB system in the CNS may also influence on the peripheral tissues including liver and the adipose tissue, resulting in affecting obesity-related diseases. The gene discussed is NTRK2; the disease is obesity due to melanocortin 4 receptor deficiency.