PINK1 and Parkinson disease: The appearance of dysfunctional mitochondria in Parkin- and PINK1-deficient astrocytes might be related to mitophagy defects, and this might further lead to a decrease in astrocyte proliferation, causing sparser distribution of GFAP-positive astrocytes in the SN and possibly contributing to the development of PD due to the delay of astrocyte-mediated repair of the brain microenvironment [122–124].