KCNJ2 and atrial fibrillation: Although KCNE1-5 and KCNJ2 mutation have been demonstrated by Ellinor et al. [64] to rarely cause typical atrial fibrillation in a referral clinic population, impairment of the KCNJ2, KCNJ5, and KCNJ8 channels, responsible for the resting membrane potential, has been demonstrated to promote AF initiation [65,66,67,68].