FXYD1 and Arrhythmia: Transgenic mice with unphosphorylatable PLM have increased incidence of pacing-induced arrhythmias (Pavlovic et al., 2013b), corresponding to the finding that PLM KO have increased amount of triggered arrhythmias after beta-adrenergic stimulation, as PLM phosphorylation protects against Na+ and Ca2+ overload (Despa et al., 2008).