Unfortunately, a relatively large proportion of IBD patients are intolerant to thiopurines and in this group, anti-TNF/thiopurine combination therapy is not possible.6 In an attempt to identify an alternative for this combination therapy, we used the induction of regulatory macrophages as a screening tool and analysed the Pharmakon 1600 library for compounds that promoted anti-TNF mediated development of regulatory macrophages. This evidence concerns the gene TNF and inflammatory bowel disease.