IL2 and Autoimmunity: This results in their robust expansion and functional enhancement, thereby promoting immunosuppression and potentially antagonizing antitumor immunity.2 14 33 Accordingly, CD25-biased IL-2 agonists have been predominantly used to expand Tregs in settings of autoimmunity and transplantation.28 35 Designing IL-2 variants that can engage CD25 on tumor-specific T cells while minimizing Treg activation remains a central goal in engineering this cytokine.