IL13 and asthma: Moreover, variation in the promoter, -589C/T (also referred to as -590C/T) [12], intron 2, +3017G/T [13], and 5'-untranslated region (UTR), +33C/T [14], of the IL4 gene and in the promoter, -1112C/T (also referred to as -1055C/T) [15], and coding region, Arg130Gln (also referred to as Arg110Gln) [16,17], of the IL13 gene have been associated with asthma and atopic phenotypes in many studies (reviewed in ref[18].