GLB1 and Parkinson disease: Enzymatic activity of beta-galactosidase rose significantly after ambroxol treatment in control [median 60% increase (IQR 50–60%), Mann-Whitney U-test P = 0.035], Gaucher disease [median 50% increase (IQR 45–100%), P = 0.04] and Parkinson’s disease with GBA mutation [median 70% increase (IQR 36–100%), P = 0.03].