In a recent paper published in Cell, Matheoud et al. demonstrated that, in response to cellular stress, self-antigens can be extracted from mitochondria via mitochondrial-derived vesicles and presented at the cell surface to trigger an immune response; this pathway, termed mitochondrial antigen presentation (MitAP), is repressed by PINK1 and Parkin. These findings implicate autoimmune mechanisms in Parkinson's disease.