The FUT2 gene (originally named the Se gene) expresses galactoside 2-alpha-L-fucosyltransferase 2 present on the Golgi membrane. FUT2 catalyses the α1,2 addition of fucose (Fuc) to Type 1 and Type 2 oligosaccharide chains, thereby playing a role in Lewis blood group determination (Kukowska-Latallo et al. 1990). Here, the addition of fucose to the terminal galactose (Gal) of the Lewis A antigen (LeA) in an α1,2 linkage forms the Lewis B antigen (LeB) (Kelly et al. 1995, Koda et al. 1997). LeB is found only in secretors in around 80% of Europeans. LeB is only formed when an individual inherits both FUT3 (Le) and FUT2 (Se) genes and around 80% of individuals inherit FUT2.