FUT2 and inflammatory bowel disease: Moreover, FUT1 and FUT2 have an apparent difference in acceptor specificity, and two types of H antigen precursors (type 1 and type 2) were regulated by the H enzyme encoded by the FUT2 and FUT1 gene, respectively, i.e., the acceptor specificity of FUT1 is type 2 chains (galactose-β-1→ 4-N-acetyl-glucosamine, N-acetyl-lactosamine) (GBD 2017 Inflammatory Bowel Disease Collaborators, 2020); in contrast, FUT2 gene-specified enzyme is more vigorous on type 1 (galactose-β-1→ 3-N-acetyl-glucosamine, lacto-N-biose) structures (Kyprianou et al., 1990).