Although other studies have investigated how JAK2 modulates the Nav1.6 channels in hippocampal CA1 pyramidal neurons [58], the Kv1.3 channels in CHO-cells [59], the BK [60], CIC-2 [61], and epithelial Na channels [62] in Xenopus oocytes, and the Ca current in MCF-7 breast carcinoma cells [63], how JAK2 modulates the rapidly activating delayed rectifier K current (IKr) in cardiomyocytes remains unknown. Here, JAK2 is linked to breast carcinoma.