In a study on CPVT, it was mentioned that SK4 channel blockers protected calsequestrin 2 (CASQ2, the gene predisposing to CPVT), CASQ2-D307H KI and CASQ2 KO mice from deleterious polymorphic ventricular tachycardia (PMVT). Here, CASQ2 is linked to polymorphic ventricular tachycardia.