PLIN3 (perilipin 3) is a structural component of lipid droplets (LDs) that plays essential roles in lipid metabolism and cellular energy homeostasis 1. The protein functions as a coat protein on lipid droplets and is required for their formation and maintenance 1. PLIN3 serves as a critical regulator of lipophagy, the selective autophagy of lipid droplets, by acting as a docking protein for autophagy machinery including ATG16L and FYCO1 2. The protein undergoes phosphorylation at Y251 by choline kinase alpha 2 (CHKα2), which promotes its dissociation from lipid droplets and subsequent degradation via Hsc70-mediated autophagy, thereby facilitating lipolysis 1. Additionally, mTORC1 phosphorylates PLIN3 to enhance lipid droplet degradation and protect against hepatosteatosis 2. PLIN3 is widely expressed across tissues and serves as a marker for nascent lipid droplets 3. In pathological contexts, PLIN3 expression is associated with disease progression - it accumulates in microglial lipid droplets during diabetes-associated cognitive impairment 4 and its downregulation by ACSS3 helps repress prostate cancer progression 5. The protein's dysfunction contributes to metabolic disorders including non-alcoholic fatty liver disease through impaired autophagy mechanisms 6.