Histology showing red and WP areas in Dhh^−/− and WT spleens, before and after induction of stress-induced erythropoiesis. Parafin-embedded spleen sections were stained with hematoxilin and eosin, to identify WP areas, which stained deeper purple, and RP areas, which stained pink. Typical WP and RP are illustrated in panel A. Left column (A,C,E,G,I) represents typical histology in WT spleens; and right column (B,D,F,H,J), typical histology in Dhh^−/− spleen, without treatment (A-B) and during a time course after induction of stress erythropoiesis after PHZ treatment, on day 5 (C-D), day 7 (E-F), day 9 (G-H), and day 14 (I-J). Scale is shown.