IL2 and anemia: In contrast to IL-2-KO disease, we observe no major alteration in IL-2Rα-KO BM erythrocyte precursors during early endpoint disease, although some changes were observed in late stage endpoints, despite similar physical signs of anemia, which includes an increase in precursors I/II, but a decrease in later-stage RBC progenitors (precursor IV) (Fig. 3A, Supplementary Fig. S3B).