TNF and inflammatory bowel disease: However, the lack of efficacy of other anti-TNF drugs such as the soluble TNF receptor etanercept [18] and the TNF synthesis inhibitor LMP-420 [19] in human or murine IBD has raised questions about whether anti-TNF therapies in IBD work via neutralization of TNF or via some other mechanism (e.g. immunosuppression generated by cytotoxicity to TNF-expressing cells).