A longitudinal Dutch family study population with asthma, followed an average of 26.5 years, with polymorphisms in both the IL-4Rα gene (S478P) and IL-13 at the-1112 promoter region (also described as - 1111,-1055) (rs1800925) demonstrate an odds ratio 4.87 times greater for the development of asthma versus individuals without these associated genotypes (P = 0.0004) [109]. Here, IL13 is linked to asthma.