Upregulation of IKs has been identified in patients with chronic atrial fibrillation (AF) (Caballero et al., 2010; González de la Fuente et al., 2013), and mutations to KCNQ1 have been shown to underlie lone AF (Chen et al., 2003; Lundby et al., 2007; Das et al., 2009). Here, KCNQ1 is linked to atrial fibrillation.