EXOC3L1 (exocyst complex component 3-like 1) is a ubiquitously expressed protein that primarily functions as part of the exocyst complex, regulating insulin secretion and peptide hormone secretion through its role in regulated exocytosis 1. The protein localizes to secretory granules and participates in SNARE-mediated trafficking, particularly facilitating lipid receptor trafficking in vascular endothelium 2. Genetically, EXOC3L1 variants are associated with HDL cholesterol concentrations in African Americans, with a splice donor region SNP (rs868213) showing significant association with HDL levels 2. Functionally, EXOC3L1 shares 53% amino acid similarity with Sec6, though unlike Sec6, overexpressed EXOC3L1 spontaneously induces apoptosis through caspase-3 activation without requiring external apoptotic stimuli 1. In disease contexts, EXOC3L1 expression is significantly elevated in esophageal squamous cell carcinoma and multiple tumor types, where high expression correlates with worse prognosis and serves as an independent prognostic predictor 34. Mechanistically, EXOC3L1 may promote tumor progression through NOTCH and PI3K-AKT signaling pathways while correlating with immune cell infiltration patterns 4. Notably, reduced EXOC3L1 expression associates with poor chemotherapy response in gastric cancer 5, suggesting dual roles in both tumor biology and treatment resistance.