PRKN and type 1 diabetes mellitus: The authors also found that the myocardium of mice with T1DM expresses low levels of PTEN-induced kinase 1 (PINK1) and parkin, but high levels of the small GTPase RAB9, which suggests that the cardiomyocytes of these mice may undergo atypical mitophagy (Xu et al., 2013).