The function of FUT7 (fucosyltransferase 7, ENSG00000180549) is as follows. Catalyzes the transfer of L-fucose, from a guanosine diphosphate-beta-L-fucose, to the N-acetyl glucosamine (GlcNAc) of a distal alpha2,3 sialylated lactosamine unit of a glycoprotein or a glycolipid-linked sialopolylactosamines chain through an alpha-1,3 glycosidic linkage and participates in the final fucosylation step in the biosynthesis of the sialyl Lewis X (sLe(x)), a carbohydrate involved in cell and matrix adhesion during leukocyte trafficking and fertilization (PubMed:11404359, PubMed:15632313, PubMed:15926890, PubMed:18402946, PubMed:18553500, PubMed:29593094, PubMed:8207002, PubMed:8666674, PubMed:8752218, PubMed:9299472, PubMed:9405391, PubMed:9461592, PubMed:9473504, PubMed:9499379). In vitro, also synthesizes sialyl-dimeric-Lex structures, from VIM-2 structures and both di-fucosylated and trifucosylated structures from mono-fucosylated precursors (PubMed:9499379). However does not catalyze alpha 1-3 fucosylation when an internal alpha 1-3 fucosylation is present in polylactosamine chain and the fucosylation rate of the internal GlcNAc residues is reduced once fucose has been added to the distal GlcNAc (PubMed:9473504, PubMed:9499379). Also catalyzes the transfer of a fucose from GDP-beta-fucose to the 6-sulfated a(2,3)sialylated substrate to produce 6-sulfo sLex mediating significant L-selectin- dependent cell adhesion (PubMed:10200296, PubMed:8752218). Through sialyl-Lewis(x) biosynthesis, can control SELE- and SELP-mediated cell adhesion with leukocytes and allows leukocytes tethering and rolling along the endothelial tissue thereby enabling the leukocytes to accumulate at a site of inflammation (PubMed:10386892, PubMed:29138114, PubMed:8666674, PubMed:9473504, PubMed:9834120). May enhance embryo implantation through sialyl Lewis X (sLeX)-mediated adhesion of embryo cells to endometrium (PubMed:18402946, PubMed:18553500). May affect insulin signaling by up-regulating the phosphorylation and expression of some signaling molecules involved in the insulin-signaling pathway through SLe(x) which is present on the glycans of the INSRR alpha subunit (PubMed:17229154). {ECO:0000269|PubMed:10200296, ECO:0000269|PubMed:10386892, ECO:0000269|PubMed:11404359, ECO:0000269|PubMed:15632313, ECO:0000269|PubMed:15926890, ECO:0000269|PubMed:17229154, ECO:0000269|PubMed:18402946, ECO:0000269|PubMed:18553500, ECO:0000269|PubMed:29138114, ECO:0000269|PubMed:8207002, ECO:0000269|PubMed:8666674, ECO:0000269|PubMed:8752218, ECO:0000269|PubMed:9299472, ECO:0000269|PubMed:9405391, ECO:0000269|PubMed:9461592, ECO:0000269|PubMed:9473504, ECO:0000269|PubMed:9499379, ECO:0000269|PubMed:9834120}.