Fucosyltransferase 4 (alpha (1,3) fucosyltransferase, myeloid-specific), also known as FUT4, CD15 and SSEA-1, is an enzyme which in humans is encoded by the FUT4 gene. The product of this gene transfers fucose to N-acetyllactosamine polysaccharides to generate fucosylated carbohydrate structures. It catalyzes the synthesis of the non-sialylated antigen, Lewis x (CD15s).
