Expression of ESAM and other endothelial antigens on fetal liver HSC fraction. The expression pattern of ESAM on Rag1/GFP− c-kitHi Sca1+ cells of E14.5 fetal liver was compared with other endothelial cell-related antigens, CD34 (A), CD31/PECAM1 (B), Endoglin (C), and Tie2 (D). The percentage of cells in subpopulation is shown. In the histograms, the staining patterns of ESAM−/Lo cells are indicated with dashed lines; those of ESAMHi cells are tinted and indicated with solid lines.