Impact of IFN-γ on hematopoiesis. Overview of hematopoietic differentiation, in which is indicated whether IFN-γ has either a stimulating (thick red arrow) or inhibitory (dotted thin red arrow) effect on a particular lineage. IFN-γ receptor α (IFNγR) is expressed on all analyzed progenitors, including HSCs, MPPs, common myeloid progenitors (CMPs), GMPs, megakaryocyte-erythroid progenitors (MEPs), and common lymphoid progenitors (CLPs) (shown in green; unpublished observations; expression of IFNγR on fully differentiated cells is not indicated in this figure). LT-HSC, long-term HSC; NK, natural killer; ST-HSC, short-term HSC.