GBA1 and Parkinson disease: Our glucocerebrosidase deficient fly model should be a valuable tool in future work aimed at understanding the mechanisms underlying the neurodegenerative diseases associated with mutations in GBA1. Although glucocerebrosidase deficiency does not result in dopaminergic neuron degeneration in Drosophila, this finding does not necessarily challenge the utility of our fly model to understand the role of glucocerebrosidase deficiency in PD.