In the recent study, Preininger and coworkers showed that 10 μM flecainide reduced spontaneous Ca2+ waves and Ca2+ spark abnormalities by lowering ΔF/F0 of these events in CPVT-specific iPSC-derived CMs carrying L3741P mutation in RYR2 [16]. The gene discussed is RYR2; the disease is catecholaminergic polymorphic ventricular tachycardia.