Expression of the IL-18 receptor on human bone marrow hematopoietic stem and progenitor cells. (A) Gating strategy and IL-18 receptor (IL-18R) expression on HSC, MPP, GMP, and CMP/MEP. (B) Bar chart of IL-18R expression in HSC, MPP, CMP/MEP, and GMP cells (n = 4). Abbreviations: HSC, hematopoietic stem cells; MPP, multi-potent progenitors; CMP, common myeloid progenitors; MEP, megakaryocyte-erythrocyte progenitors; GMP, granulocyte-monocyte progenitors.