We have recently observed that there were no significant differences in protein expression of SK3 and SK4 between ND and DM MHECs (Zhang et al., 2020) or between patients with ND and patients with DM in the atrial myocardium/coronary endothelial cells, (Liu et al., 2015, 2018, 2020) suggesting that DM may affect endothelial SK gating or trafficking instead of the total protein levels. This evidence concerns the gene KCNN4 and Norrie disease.