A review. The research of Beffagna et al. (2005), entitled 'Regulatory mutations in transforming growth factor-beta3 gene cause arrhythmogenic right ventricular cardiomyopathy type 1', is reviewed with commentary and references Beffagna et al.presented novel and exciting findings that led to three main consequences. First, they demonstrated that regulatory mutations in TGFβ3 cause arrhythmogenic arrhythmogenic right ventricular cardiomyopathy/dysplasia type 1 (ARVC/D1), adding a new brick in the wall to better understand the mol. mechanisms underlying the pathogenesis of ARVC/D in particular and the genetic causes of sudden cardiac death (SCD) in general. Secondly, they opened a new field of research on the biol. function of TGFβ3 and the contribution of specific TGFβ ligands or their combinations to the TGFβ signaling in heart development as well as in adult cardiovascular function and remodeling. This information will allow a better understanding of its role in cardiac physiol. and pathophysiol. of cardiovascular diseases. Thirdly, a better insight into genetic causes of ARVC/D and SCD holds the promise to provide new approaches to the diagnosis, and potential therapeutic interventions based on the genetic underlying cause of disease may be developed, resulting in better long-term care and survival for patients with ARVC/D.