MC4R (Melanocortin 4 Receptor) is a G protein-coupled receptor (GPCR) in the CNS that regulates appetite and metabolism by responding to hormones like α-MSH and proteins like AgRP, with genetically validated mutations that cause severe obesity. MC4R is also known to complex with inward rectifying potassium channels, whose potentiation plays a key role in neuronal cell excitability and energy homeostasis.