Creates a soluble precursor oligosaccharide FuC-alpha ((1,2)Galbeta-) called the H antigen which is an essential substrate for the final step in the soluble A and B antigen synthesis pathway. H and Se enzymes fucosylate the same acceptor substrates but exhibit different Km values. FUT2 is expressed on the surface of several human tumor cell lines such as BEL-7404, SPC-A-1, and SGC-7901.