GAL3ST1 encodes galactose-3-O-sulfotransferase 1, a sulfotransferase that catalyzes sulfate transfer to position 3 of non-reducing beta-galactosyl residues in glycosphingolipids 1. The enzyme synthesizes major myelin lipid galactosylceramide sulfate (sulfatide) and seminolipid in spermatocytes 1. GAL3ST1 is the only enzyme that sulfates sphingolipids to produce sulfatides, fundamental myelin components 2. In disease pathogenesis, GAL3ST1 has emerging relevance across multiple conditions. Genome-wide association studies identified GAL3ST1 variants as genetic risk factors for sporadic Creutzfeldt-Jakob disease (sCJD), implicating sulfatide metabolism in prion disease susceptibility 23. In Alzheimer's disease, reduced sulfatide levels correlate with disease progression; APP processing regulates GAL3ST1 expression, and sulfatide supplementation decreases amyloid-beta generation 4. GAL3ST1-produced sulfatides mediate inflammatory pain through selectin signaling in the spinal cord 5. In cancer, GAL3ST1 expression is enriched in pancreatic cancer precursors and associates with altered sphingolipid metabolism relevant to tumor progression 6. ASIV-induced GAL3ST1 upregulation via FOXA1 transcriptional activation inhibits triple-negative breast cancer growth 7. Clinically, GAL3ST1 represents a potential biomarker and therapeutic target in neurodegenerative diseases and cancer, though prognostic utility in renal cell carcinoma remains uncertain 8.