“…In humans, polymorphism has been identified in a wide range of genes encoding such mediators, including IL-1␣, 1 IL-1, 2 the IL-1 receptor antagonist, 2 IL-2, 3 IL-3, 4 IL-4, 5-7 the IL-4 receptor 8 the common  subunit of the GM-CSF, IL-3 and IL-5 receptors, 9 IL-6, 10 IL-10, 11 IL-13, 12 IFN-␥, 13,14 TNF-␣, 15 TNF-, 16 the TNF receptor, 17 TGF-, 18 22 While some of this diversity may represent random genetic variation, evidence suggests that at least some of these polymorphisms do influence the expression of the genes involved. 2,13,15,20,[23][24][25][26] Logically, it would be expected that these polymorphisms might therefore exert an influence on the course and severity of immunologic disease. Accumulating evidence suggests that this is indeed the case.…”