However, since there is evidence that TWEAK:Fn14 binding can stimulate either “pro-tumorigenic/metastatic” or “anti-tumorigenic/metastatic” cellular responses in vitro, depending on the cancer cell line under investigation, it is unclear at this time whether (i) a therapeutic agent should inhibit or stimulate Fn14 signaling, and (ii) an agent can be developed for general use in all patients harboring Fn14-positive tumors, regardless of the cancer type. This evidence concerns the gene TNFSF12 and cancer.