We found increased α‐synuclein release from iPSC‐derived dopaminergic neurons across all homozygous GBA1 mutant lines (N370S/N370S, L444P/L444P, and D409H/D409H) and PD lines (iPD and PD N370S/WT), in comparison with WT cells. Here, GBA1 is linked to Parkinson disease.