Numerous studies have described the improvement of IL-2 therapy in cancer through engineering approaches, including the design of IL-2 muteins with biased cytokine activity (reducing CD25 binding and/or increasing CD122 binding),8polyethylene glycol (PEG)ylation of IL-2 and variants thereof10 or design of IL-2/CD25 fusion proteins (FPs).11 This evidence concerns the gene IL2RA and cancer.