Expanding our analysis to the accumulation of high‐molecular‐weight oligomeric forms of α‐synuclein, we observed significant accumulation in all homozygous GBA1 mutant iPSC‐derived dopaminergic neurons (N370S/N370S, L444P/L444P, and D409H/D409H), as well as in dopaminergic neurons from PD patients (both iPD and PD N370S/WT), when compared with WT cells. The gene discussed is GBA1; the disease is Parkinson disease.