Blocking α4β7 in vivo prevented the migration of IL-17+ γδTc but not αβTc into mouse pleura, and also blocked transmigration of γδTc across VCAM-1- and MadCAM-1-expressing endothelium toward CCL25 or cell-free pleural washes from mice in whom an allergic reaction had been induced (77). This evidence concerns the gene IL17A and allergic disease.