In conclusion, we have shown that the specific inhibitor LRRK2 PF-475 restores GCase activity through downregulation of RAB10, reduces lysosome accumulation, and reverses the GBA1 K198E-induced PD phenotype (e.g., p-Ser129 α-Syn, DJ-Cys106-SO3, low ∆Ψm, and CC3-positive cells) in skin fibroblasts. The gene discussed is GBA1; the disease is Parkinson disease.