PINK1 and Parkinson disease: Systematic genetic screens covering ~80% of the entire genome were performed to identify modifiers of the PD phenotype in Drosophila. From the screen, we identified a number of cytological regions that interact with park and/or Pink1. Fine mapping in selected PD-interacting cytological regions was performed, which identified debra, Pi3K21B and β4GalNAcTA as novel PD-interacting genes.