This is made possible by the excellent accessibility of the CD13 target (the luminal side of the endothelial lining of tumor vasculature, thus not beyond the BBTB) and the high avidity of the interactions among NGR-TNF, CD13 and TNF-receptors, co-expressed on the endothelium of the tumor vasculature. The gene discussed is ANPEP; the disease is neoplasm.