LRRK2 is a serine/threonine-protein kinase that functions as a critical regulator of multiple cellular processes implicated in Parkinson's disease (PD) pathogenesis 1. The kinase phosphorylates a broad range of proteins involved in neuronal plasticity, innate immunity, autophagy, and vesicle trafficking 2. A primary mechanism involves LRRK2's regulation of RAB GTPases; the kinase phosphorylates RAB3, RAB5, RAB8, RAB10, and RAB29, modulating their activity and governing endolysosomal dynamics and ciliogenesis 3. LRRK2 is dynamically recruited to stressed or damaged lysosomes through GABARAP-CASM pathway interactions, where it phosphorylates RAB substrates to promote lysosomal content release and suppress pathological enlargement 4. Additionally, LRRK2 suppresses lysosomal degradative activity through MiT-TFE transcription factor inhibition, with hyperactive disease mutants exacerbating this suppression 5. Mutations in LRRK2 represent the most common genetic cause of familial PD and are implicated in sporadic disease; LRRK2-PD exhibits variable pathology with inconsistent Lewy body pathology but marked Alzheimer-type changes 1. Beyond PD, LRRK2 dysfunction contributes to acute kidney injury through MFN2-dependent mitochondrial fragmentation 6. Emerging LRRK2-targeted therapies aim to normalize kinase activity and restore lysosomal homeostasis.