GLT8D1 (glycosyltransferase 8 domain containing 1) is a Golgi-localized glycosyltransferase that catalyzes the transfer of galactose residues from UDP-galactose onto GalNAc and GlcNAc structures 1. This enzymatic activity modulates protein glycosylation, which affects multiple cellular processes including protein degradation and cell migration. Mechanistically, GLT8D1 functions through N-linked glycosylation to stabilize CD133, a glioma stem cell marker, by preventing its degradation via the endosomal-lysosomal pathway 2. Its enzymatic activity directly promotes glioblastoma cell migration through glycosylation of cytoskeleton and intracellular transport-associated proteins 1. GLT8D1 has been identified as a genetic risk factor for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, though population-specific variation exists; mutations appear uncommon in Australian and Chinese cohorts 34, but the gene was discovered in European ALS families 5. Evidence suggests digenetic inheritance models where GLT8D1 variants co-occur with mutations in other ALS genes 6. Clinically, GLT8D1 overexpression serves as an independent prognostic biomarker associated with poor outcomes in multiple cancers: glioblastoma, gastric cancer, and melanoma 278. GLT8D1 is induced by hypoxia through HIF-1α signaling and correlates with tumor immunity and immune checkpoint expression 27. Inhibiting GLT8D1 shows therapeutic potential in glioma models, suggesting it as a candidate therapeutic target.