The biologicals, e.g., anti-TNF antibody (infliximab, adalimumab, certolizumab), anti-IL-12/23 (ustekinumab), and anti-α4β7 integrin antibody (vedolizumab) have been approved for Crohn's disease targeting the Th1/Th17 mediated inflammation and the diapedesis of the leukocytes in the intestinal mucosa respectively. This evidence concerns the gene TNF and Crohn disease.