IL-33 an IL-1 family member together with IL-1β and IL-18 mediates its biological effects via IL-1 receptor-like 1 (ST2) and has been reported to trigger production of the main allergy signature cytokines IL-4, IL-5, and IL-13 by Th2 cells, basophils, and mast cells [4]–[7]. This evidence concerns the gene IL1B and allergic disease.