Mitophagy has been well-documented by numerous groups in several immortalized cell lines overexpressing parkin.8, 62 However, the nature of this process in neurons, which express endogenous parkin, has been somewhat controversial.16, 19, 63 Our data suggest that the scale of mitochondrial turnover in primary cells expressing endogenous parkin may be relatively muted when compared with cancer cell lines overexpressing human parkin. The gene discussed is PRKN; the disease is cancer.