Notably, human DSG-2 mutations are associated with cardiac arrhythmia (Schinner et al., 2020), and genetic deletion of DSG-2 leads to arrhythmogenic cardiomyopathy and heart failure in mice (Pilichou et al., 2009); thus, whether the exosome-mediated transfer of DSG-1 to cardiomyocytes contributes to the benefit of MSC therapy warrants continued investigation, particularly since MSC exosomes appear to reduce the arrhythmogenicity of human cardiomyocytes (Sattayaprasert et al., 2020). The gene discussed is DSG2; the disease is chronic obstructive pulmonary disease.