FUT7 encodes an α1,3-fucosyltransferase that catalyzes the terminal fucosylation step in sialyl Lewis X (sLeX) biosynthesis, a carbohydrate ligand critical for leukocyte trafficking. The enzyme transfers L-fucose from GDP-fucose to N-acetylglucosamine residues on glycoproteins and glycolipids, enabling sLeX-mediated adhesion to E- and P-selectins on endothelial cells and facilitating leukocyte tethering and rolling during inflammatory responses. FUT7 also regulates embryo implantation through sLeX-dependent adhesion of embryonic cells to endometrium and may modulate insulin signaling through modifications of insulin receptor glycosylation. In inflammatory bowel disease, FUT7 expression is reduced in regulatory T cells (Tregs) from patients with active disease, and restoring FUT7 expression in Tregs enhances their intestinal homing and immunosuppressive capacity 1. By contrast, FUT7 is upregulated in acute lymphoblastic leukemia, where it promotes leukemic cell adhesion and invasion through integrin/FAK/AKT pathway activation 2. In bladder urothelial carcinoma, elevated FUT7 correlates with poor survival and increased immune infiltration 3. Recent therapeutic approaches leverage FUT7-engineered extracellular vesicles to enhance sLeX expression and improve diabetic wound healing through E-selectin-mediated targeting of endothelial cells 4. Blood-based FUT7 hypomethylation has emerged as a potential biomarker for early-stage lung cancer detection 5.