Furthermore, regression analysis performed between GCase activity and age of disease onset (PD, r = − 0.1259, p = 0.5487; gPD-GBA N370S, r = 0.7724, p = 0.1258) (Additional file 1: Fig. S2A, Additional file 2), and GCase activity and disease duration (PD, r = 0.3403, p = 0961; gPD-GBA N370S, r = − 0.7546, p = 0.1404) (Additional file 1: Fig. S2B, Additional file 2) across the idiopathic PD and gPD-GBA N370S cells showed no significant correlation between the variables in both groups of PD cells. Here, GBA1 is linked to Parkinson disease.