TNF and Crohn disease: This is consistent with a report showing that infliximab, a monoclonal antibody against TNF-α, increases apoptosis of activated T lymphocytes in the gut mucosa of patients with Crohn's disease [13, 14], although it is possible that infliximab induced apoptosis of activated T cells by antibody-dependent cell-mediated cytotoxicity or complement-dependent cytotoxicity in vivo, because our results showed an overexpression of tmTNF-α in activated T cells (Figure 1C and 1G).