Erythroblastic islands reconstituted with c-Maf^+/+ erythroblasts were immunostained. The number of c-Maf^+/+ erythroblasts surrounding each c-Maf^+/+ or c-Maf^−/− macrophage is shown. c-Maf^+/+ erythroblasts surrounding c-Maf^−/− macrophages were significantly reduced as compared with those seen for c-Maf^+/+ macrophages. See the entire figure in the article by Kusakabe et al on page 1374.