Variants in Fut-2, an enzyme encoding galactoside 2-alpha-l-fucosyltransferase-2, have also been suggested to confer increased susceptibility to PSC (as well as Crohn's disease), although fall short of reaching significance at a genome-wide level.77, 78 Fucosyltransferase variants alter the recognition and binding of various pathogens to carbohydrate receptors on the mucosal surface and are associated with changes in the commensal phyla in affected patients with PSC characterized by elevated Firmicutes and reduced Proteobacteria. This evidence concerns the gene FUT2 and Crohn disease.