Intestinal infection of bacteria also led to enhanced mitochondrial antigen presentation and autoimmune response in PINK knockout mice compared with control,269 which may explain the increased CD8+ T cells in PD patients.270 In conclusion, loss of activities in PRKN and PINK1 during PD may increase mito-inflammation and enhance mitochondrial antigen presentation, promoting the development of PD. The gene discussed is CD8A; the disease is Parkinson disease.