However, as TREG cells and NK cells express different IL-2 receptors (IL-2Rα and IL-2Rβ, respectively) efforts have been made to synthesise chimeric IL-2–IL-2Rβ or mutant IL-2 that preferentially binds to the IL-2Rβ in order to selectively activate NK cells; these agents show improved anti-tumour action, but have not been well studied in metastatic settings yet.115,116. Here, IL2 is linked to neoplasm.