PINK1 and Parkinson disease: For instance, monkeys with mutations in the PINK1 gene, which can lead to early onset Parkinson’s disease, exhibit neurodegeneration, whereas PINK1 knockout mice do not display such degeneration.35 Similarly, monkeys with mutations in the CHD8 gene, which are responsible for autistic behaviors and macrocephaly in humans, exhibit abnormal gliogenesis, a phenomenon absent in mutant mouse models.36 These discoveries provide compelling evidence for the use of non-human primates as an essential model for investigating neuropathology and pathogenesis-related to AD.