Parkin-null (park−/−) Drosophila are a powerful model of PD because they have a decreased lifespan, a severe motor phenotype and selective degeneration of PPL1 dopaminergic neurons (Whitworth et al., 2005; Houlihan et al., 2022; Cackovic et al., 2018). The gene discussed is PRKN; the disease is Parkinson disease.