We anticipated that the A, B or AB blood group, secretor (FUT2) and Lewis positive (FUT3) genotypes would be found in higher prevalence in patients with severe lung phenotype, because genotypes associated with functional fucosyltransferases for synthesis of pertinent glycoproteins have been shown to be associated with increased propensity towards infection with P. aeruginosa, H. influenzae and S. aureus. This evidence concerns the gene FUT2 and infection.