The Lasting Impact of IL-2: Approaching 50 Years of Advancing Immune Tolerance, Cancer Immunotherapies, and Autoimmune Diseases

Background The discovery of interleukin-2 (IL-2) and its receptor (IL-2R) almost 50 years ago revolutionized immunology, marking a pivotal moment in understanding T cell biology and immune regulation. Initially identified as a T cell growth factor, IL-2 unveiled critical insights into cytokine-mediated immune cell proliferation and differentiation.