Expression of PRR2 in human bone marrow cells and endothelial cells. (A) Bone marrow cells were doubled stained with the indicated MoAbs and the MoAb R2.477 as described in Materials and Methods. Fluorescence density plots were gated on specific regions defined on scatter plot. The bottom-left quadrant was defined according to an isotypic-matched control antibodies. The percentage represents the number of PRR2-expressing cells in each lineage. (B) FACS analysis of PRR2 and PECAM-1 expression in HUVEC. HUVEC were stained either with the MoAb R2.477 or the MoAb anti–PECAM-1. Each fluorescence distribution was superposed and compared with the background fluorescence distribution of an isotypic-matched control antibody.