Characterization of the CD34posCD31neg-derived population. After culture in serum-containing medium, CD34posCD31neg cells differentiated into cells expressing mesenchymal/pericyte markers as assessed by flow cytometry (A; n.d. indicates not detectable; white, isotype control, gray, specific antibody staining [as indicated]) and immunocytochemistry (B; scale bar=50 μm, nuclei: DAPI [blue]). α-SA indicates α-sarcomeric actin; α-SMA, α-smooth muscle actin. Results are representative of 4 (A) or 3 (B) experiments.