Rabbit IL-2 (Interleukin-2) is a central T cell–derived cytokine that regulates lymphocyte proliferation, differentiation, and immune homeostasis in rabbits (Oryctolagus cuniculus). IL-2 is produced primarily by activated CD4⁺ and CD8⁺ T lymphocytes following antigen recognition and costimulatory signaling, and it functions through the IL-2 receptor complex (IL-2Rα/CD25, IL-2Rβ/CD122, and the common γ chain/CD132) to promote clonal expansion of antigen-specific T cells, enhance cytotoxic T lymphocyte and natural killer (NK) cell activity, and support development and maintenance of regulatory T cells (Tregs). In healthy rabbits, basal IL-2 expression is generally low but increases during infection, vaccination, and immune stimulation. Altered IL-2 responses have been observed in models of tuberculosis, atherosclerosis, ocular inflammation, autoimmune-like disease, and tumor immunology. Rabbits serve as valuable translational models for cardiovascular disease, infectious disease, and immunogenicity studies. In biomedical research, rabbit IL-2 is widely used as a biomarker of T cell activation and cell-mediated immunity and supports investigation of vaccine efficacy, immune regulation, and immunotherapeutic strategies.