ITGA4 and Crohn disease: The prognostic relevance of CD49d in CLL may have also therapeutic implications, envisioning the use for CLL patients of Natalizumab (TYSABRI, Biogen Idec, Cambridge, MA and Elan Pharmaceuticals, South San Francisco, CA, USA), a humanized anti-CD49d monoclonal antibody already available and currently employed in autoimmune diseases such as multiple sclerosis and Crohn's disease [153].