KCNN4 and obesity due to melanocortin 4 receptor deficiency: Regarding the role of KCa channels in the endothelium-dependent relaxations of coronary arteries in obesity both impaired [30] and preserved function [31] have been reported for the large conductance KCa (BKCa) channels, while the function of endothelial SK3/IK1 channels remains largely unexplored.