text: K2.3 channels play a major role in human physiology, particularly in smooth muscle relaxation. The expression level of K2.3 channels in the endothelium influences arterial tone by setting arterial smooth muscle membrane potential. The sustained activity of K2.3 channels induces a sustained hyperpolarisation of the endothelial cell membrane potential, which is then carried to nearby smooth muscle through gap junctions. Blocking the K2.3 channel or suppressing K2.3 expression causes a greatly increased tone in resistance arteries, producing an increase in peripheral resistance and blood pressure.