We used induced pluripotent stem cells (iPSC)‐derived dopaminergic neuronal cultures obtained from individuals representing different groups, including healthy individuals (wild‐type (WT) lines), GBA1 homozygous patients with non‐neuronopathic Type I GD (N370S/N370S) and neuronopathic Type III GD (L444P/L444P and D409H/D409H), obligate heterozygous carriers (N370S/WT, L444P/WT, and D409H/WT), idiopathic PD patients, PD patients carrying heterozygous GBA1 mutations (N370S/WT), and healthy individuals. This evidence concerns the gene GBA1 and Parkinson disease.