In a recent study of human erythroid cells [18], a novel population of cells termed erythroid-derived myeloid cells (EDMCs) was characterized as "transcriptionally indistinguishable from their myeloid-derived counterparts." These cells emerge in cancer patients from CD45-positive erythroid cells, induced by tumor-derived granulocyte-macrophage colony-stimulating factor (GM-CSF). The gene discussed is CSF2; the disease is neoplasm.