This view is supported by the results showing that 5a-HSA could enhance, in the WEHI-164 fibrosarcoma model, the anti-tumor activity of S-NGR-TNF, a targeted inflammatory cytokine consisting of tumor necrosis factor-alpha (TNF) fused to a tumor vasculature-homing peptide containing the NGR sequence [21]. Here, RTN4R is linked to fibrosarcoma.