Mice deficient in IL-2 (IL-2-KO) or its receptor (IL-2Rα-KO or IL-2Rβ-KO) develop spontaneous, multi-organ autoimmune disease, including autoimmune hemolytic anemia (AIHA), bone marrow (BM) failure (BMF), inflammatory bowel disease, and dacryoadenitis3,8–13. This evidence concerns the gene IL2RB and autoimmune hemolytic anemia.