The mitochondria-resident protein, PTEN-induced putative kinase protein 1 (PINK1), mediates phosphorylation and activation of parkin; therefore, loss-of-function mutations in PINK1 lead to impaired parkin activity and are associated with a PD phenotype similar to that of mutated PRKN-related PD (Kamienieva et al., 2021). Here, PINK1 is linked to Parkinson disease.