Expression of EPOR in human FL EBI macrophages. (A) Representative plot of CD14 vs CD16 in human FL CD45⁺ cells. (B) Representative plot of CD163 vs SSC-A of the CD14⁺CD16⁺ cells. Top, FMO; bottom: CD163 expression. (C) Representative plot of EPOR vs SSC-A of CD163⁺ cells. Upper panel: FMO; lower panel: EPOR expression; (D) Representative cytospin images of sorted human FL CD163⁺EPOR⁺ macrophages and CD163⁺EPOR⁻ macrophages. N = 5. (E) Top: a representative EBI structure showing CD163⁺EPOR⁺ was surrounded by multiple GPA⁺ erythroid cells; bottom: a representative image showing the CD163⁺EPOR⁻ macrophage was surrounded by 1 erythroid cell. (F) Quantitative analyses of human FL EBIs. Quantitative analyses of EBIs were performed using 200 EBIs from 2 independent experiments. FMO, fluorescence minus one.