Glycosyltransferases that mediate the regio- and stereoselective transfer of sugars, such as the fucosyltransferases, determine cell surface-carbohydrate profiles, which are essential interfaces for biological recognition processes. Fucosyltransferases (FucTs) catalyze the covalent association of fucose to different positional linkages on sugar acceptor molecules. The carbohydrate moieties that are generated are covalently attached to cell surfaces and are necessary to ensure a surface contour that satisfies a variety of physiological roles. FucT-XI (fucosyltransferase XI), also known as alpha-(1,3)-fucosyltransferase 11 or galactoside 3-L-fucosyltransferase 11, is a 492 amino acid single-pass type II membrane protein that belongs to the glycosyltransferase 10 family. Localizing to Golgi apparatus, FucT-XI may act as a fucosyltransferase and exists as two alternatively spliced isoforms. The gene encoding FucT-XI maps to mouse chromosome 14 A3.