B3GNT8 is a Golgi-resident glycosyltransferase that catalyzes the addition of N-acetylglucosamine to the non-reducing terminus of galactose in multiantennary N-glycans, particularly tetraantennary and 2,6-triantennary structures, thereby elongating poly-N-acetyllactosamine chains. The enzyme functions through heterodimer formation with other β3-N-acetylglucosaminyltransferases, which enhances its enzymatic activity. B3GNT8 expression is dramatically elevated in colorectal cancer tissues compared to normal tissue 1, and its overexpression promotes gastric cancer cell proliferation and invasive capacity by upregulating matrix metalloproteinase-2 while suppressing its inhibitor, TIMP-2 2. Conversely, B3GNT8 knockdown significantly reduces gastric cancer cell growth and tumorigenicity in vivo 3. In triple-negative breast cancer, elevated B3GNT8 mRNA levels inversely correlate with relapse-free and overall survival 4. Recent evidence suggests B3GNT8 plays a protective role in aging through genetic association studies 5 and may reduce atrial fibrillation risk 6. B3GNT8 additionally emerged as a candidate causal gene in migraine pathogenesis through multi-tissue transcriptomic analysis 7 and as a novel liquid biopsy biomarker for prostate cancer diagnosis, outperforming PSA in diagnostic accuracy 8. At the intestinal epithelial level, B3GNT8 maintains homeostasis by preserving tight junction integrity and Paneth cell function; its deficiency increases susceptibility to colitis 9, suggesting therapeutic potential in inflammatory bowel disease.