LRRK2 and Parkinson disease: The reality is that the LRRK2 gene expression in human PBMCs is high under homeostatic conditions, and increased LRRK2 protein levels after stimulation exhibit its induction plays a crucial part in regulating effector functions; hence, Caution should be exercised in targeting LRRK2 as an essential therapeutic intervention in PD as up to now imprecise whether the raised LRRK2 protein levels in immune cells are deleterious or protecting function in the immune system [201, 202].