CaMKII-mediated RyR2 Ca2+ leak is involved in arrhythmogenesis in a large variety of pathological states, including Duchenne muscular dystrophy (Ather et al., 2013), chronic β-adrenergic stimulation (Grimm et al., 2015), atrial fibrillation (Chelu et al., 2009) and arrhythmias resultant from cardiac glycoside treatment (Gonano and Petroff, 2014). The gene discussed is CAMK2G; the disease is atrial fibrillation.