PIMREG and Ventricular arrhythmia: A previous study found that Klf15-deficient mice showed perturbed CM rhythmic activity and were susceptible to ventricular arrhythmias, similarly to the effects seen in Fam64a TG mice (Figures 4C–4F), which were considered to reflect suppressed KChIP2 activity (Jeyaraj et al., 2012).