Further supporting a cardioprotective role for RGS4 against AFib pathogenesis, in addition to its role in IKACh regulation, is the fact that RGS4 is essential for the suppression of pro-arrhythmogenic Ca2+ signaling by Gq/11 protein-coupled receptors, primarily the endothelin ETA and angiotensin II AT1 receptors, in the heart [114]. The gene discussed is RGS4; the disease is atrial fibrillation.