Accordingly, multiple engineered variants of IL-2-based therapeutics, such as IL-2 immunocomplexes (IL2ICx), IL-2 immunocytokines, or IL-2 muteins, were developed to avoid the adverse effects of IL-2 and to target only one arm of the immune system (i.e., cytotoxic CD8+ T and NK cells for anti-cancer treatment or Tregs in the treatment of autoimmune diseases) (reviewed in [16]). Here, IL2 is linked to cancer.