α4β1 integrin is expressed on a variety of blood cells, and its prototypic counter-receptor ligand vascular cell adhesion molecule-1 (VCAM-1) reflects its involvement in adhesion to the vascular endothelium during chronic inflammatory diseases, such as psoriasis, rheumatoid arthritis, asthma, and allergy [17]. This evidence concerns the gene VCAM1 and Allergy.