CASQ2 and cardiac arrhythmia: Our data showed that restoration of Casq2 at a median (nonzero) distance of 53.8 μm from the nearest Cntn2-positive (Purkinje) cells was sufficient to prevent arrhythmias, indicating that distal (epicardial) cardiomyocytes, despite lacking Casq2, are not the cellular trigger for CPVT.