TGFB1 and neoplasm: We show that this conjugate (called 5a-HSA) can efficiently bind αvβ6+ and/or αvβ8+ cancer cells as well as αvβ8+ immunosuppressive Tregs, and, consequently, inhibits TGFβ activation by these cells in vitro. Furthermore, we demonstrate that 5a-HSA can reduce TGFβ activation in tumors and induce strong anti-tumor effects in various in vivo murine models, either when injected alone or in combination with S-NGR-TNF, a targeted inflammatory cytokine.