CAMK2G and obesity due to melanocortin 4 receptor deficiency: Under obesity/hyperlipidemia conditions, CaMK II activation causes downregulation of ion channels protein, such as Kv4.2, Kv4.3, Kv1.5, Kv2.1, and Cav1.2, and results in prolonged repolarization and action potential duration (APD), and eventually leads to detrimental remodeling of ion channels (38, 85).