The voltage-gated Kv1.3 potassium channel has recently been targeted for obesity control, as mice lacking Kv1.3 or treated with a Kv1.3 blocker are protected from high-fat diet-induced obesity (Upadhyay et al., 2013; Xu et al., 2003). Here, KCNA3 is linked to obesity due to melanocortin 4 receptor deficiency.