Natalizumab, an integrin α4β1 (VLA‐4) antagonist that interferes with leucocyte trafficking by blocking the interaction between VLA‐4 and vascular cell adhesion molecule 1 (VCAM‐1), has been used in the therapy of inflammatory bowel disease and multiple sclerosis.64, 65. The gene discussed is VCAM1; the disease is multiple sclerosis.