EPDR1 (ependymin related 1) is a secreted glycoprotein that functions as a batokine regulating metabolic and immune processes across multiple tissues. Structurally, EPDR1 binds anionic lipids and gangliosides at acidic pH and localizes to lysosomes and extracellular regions 1. In pancreatic β-cells, EPDR1 promotes glucose-stimulated insulin secretion by channeling pyruvate through the mitochondrial TCA cycle, with expression upregulated in type 2 diabetes and obesity 2. EPDR1 also functions as an adipose-derived endocrine factor that regulates systemic cardiometabolic homeostasis, influencing blood lipid and glucose levels 3. In cancer biology, EPDR1 promotes tumor progression through distinct mechanisms: in hepatocellular carcinoma, it enhances PD-L1 expression and immune evasion by inhibiting TRIM21-mediated degradation of IκB kinase-β 4; in gastric cancer, it activates STAT3-mediated fatty acid metabolic reprogramming 5; and in colorectal cancer, it promotes proliferation and invasiveness 6. Additionally, EPDR1 drives fibroblast dysfunction in idiopathic pulmonary fibrosis through lysosomal dysfunction and senescence 7. EPDR1 has been identified as a genetic risk locus for primary angle-closure glaucoma 8, indicating broad disease relevance. Overall, EPDR1 represents a pleiotropic regulator with significant therapeutic potential across metabolic, immune, and fibrotic diseases.