Considering that Treg cells present in tumors can express αvβ8 and contribute to the development of an immunosuppressive microenvironment via TGFβ activation through this integrin, the bi-specific properties of 5a-HSA may represent an important advantage with respect to mono-specific αvβ6 or αvβ8 integrin ligands previously described in the literature [11, 18, 36–46], as 5a-HSA can target cancer cells expressing one or both integrins as well as Tregs. Here, ALB is linked to cancer.