KCNH2 and cardiac arrhythmia: In our work we found this implication of voltage-gated sodium and potassium channels in cardiovascular diseases (SCN2A-SCN9A-KCNH2 cluster for vascular diseases, SCN2A-SCN5A-KCNH2 cluster for cardiac arrhythmias and SCN5A-SCN4B-KCNH2 cluster for other heart diseases) (Fig. 5).