Some representative examples of flow cytometric measurements of Notch ligands expression by both B-ALL cells and hBM-MSCs. Representative cases of the expression of Notch ligands by both B-ALL cells and hBM-MSCs cultured alone and cocultured for 3 and 7 days, after electronic gating on either CD19⁺ B-ALL cells or CD45⁻ hBM-MSCs in 2-color flow cytometric analysis. Filled histograms indicate the staining with control human IgG. DLL indicates Delta-like ligand; and Jag, Jagged ligand.