DSG2 and Arrhythmogenic right ventricular dysplasia: In humans, heterozygous PKP2 and DSG2 mutations lead to ARVC, but in mice, homozygous deletion of Dsg2 and Pkp2 in the mouse heart is required to elicit cardiomyopathy and to define NF-κB activation, since heterozygous deletion has little phenotype in mice (27–30).