TWEAK/Fn14 signaling can also have pro-tumorigenic effects (reviewed in [4], [22]) [11], [12], [29]; accordingly, in pre-clinical studies we have demonstrated that Fn14-targeted immunotoxins have anti-tumor activity [25], [30] and Hoffmann-LaRoche Inc. has initiated a Phase I clinical trial testing the effects of an anti-TWEAK monoclonal antibody in patients with advanced solid tumors (ClinicalTrials.gov Identifier NCT01383733). Here, TNFSF12 is linked to neoplasm.