The available data show that several atrial-specific ion channel currents, such as the ultrarapid delayed rectifier K+ current (IKur, encoded by the K+ channel Kv1.5), the small-conductance Ca2+-activated K+ current (ISKCa, encoded by the SK channels), and the acetylcholine-activated K+ current (IKACh), may be novel targets to develop atrial-selective anti-AF drugs (Al-Khatib et al., 2014; Burashnikov and Antzelevitch, 2010; Diness et al., 2010). Here, KCNA5 is linked to atrial fibrillation.