TNFSF12 and Cachexia: Although TWEAK, the only known ligand of Fn14, was shown not to be required for the production of cachexia in preclinical models [7], it has previously been shown to induce the production of IL-17 and that the blockade of Fn14, by adding Fn14-Fc to cell culture medium, could effectively inhibit the production of IL-17 [19].