Firstly, KCa3.1 channels do not appear to contribute to arrhythmogenesis in the healthy heart (Schmitt et al., 2014), although one report has suggested a role for KCa3.1 channel current in cardiac pacemaker activity in a transgenic mouse model of catecholaminergic polymorphic ventricular tachycardia (CPVT) (Haron-Khun et al., 2017). The gene discussed is KCNN4; the disease is catecholaminergic polymorphic ventricular tachycardia.