PGE₂ receptors are expressed on murine and human HSPCs. (A) Representative FACS gating of Lin^neg murine bone marrow showing c-kit⁺ and Sca-1⁺ gates and SLAM (CD150⁺, CD48⁻) and CD34 gating of SKL cells. EP1-EP4 surface receptor expression on murine KL, SKL, SLAM SKL, and CD34^neg SKL cells is shown. (B) Representative FACS gating of human CD34⁺ and CD34⁺, CD38⁻ UCB cells. EP surface receptor expression on CD34⁺ and CD34⁺, CD38⁻ cells is shown.