GBA1 and Parkinson disease: There was BiP/Grp78 elevation on western blotting of Gaucher disease [median 60% increase compared with controls (IQR 20–100% increase), Mann-Whitney U-test P = 0.0016], Parkinson’s disease with GBA mutation [median 15% increase (IQR 0–50%), P = 0.0023] and non-manifesting carrier cells [median 15% increase (IQR 10–20%), P = 0.009].