IGKV1D-22 and Crohn disease: While α9 is closely associated with lymphatic development and LEC migration, the best data for integrin involvement in lymphangiogenesis involves the integrin α4β1 [20, 29], and an inhibitor of the α4-integrin natalizumab (Tysabri) has been approved for the treatment of chronic inflammatory diseases such as multiple sclerosis and Crohn's disease since 2004 [115].