Maltreated children experience detrimental physical health consequences, such as obesity and systemic inflammation,1,2 consistent with findings from experimental research in nonhuman primates exposed to early-life stress.3,4 Because leptin is a key molecule involved in the regulation of both energy balance and immunity, we investigated possible differences in leptin physiology in maltreated vs non-maltreated children. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.