VLA-4 expression by BM and mobilized PB CD34⁺ cells and cultured CD34⁺ cells. (A and B) CD34⁺ cells isolated from BM cells (solid line), and mobilized PB cells (broken line) were stained with control antibody (A) or anti–VLA-4 MoAb (B). (C and D): The cobblestone area–forming cells (solid line) and nonadherent cells (broken line) presented in Fig4 were stained with anti-CD34 MoAb and with control antibody (C) or anti–VLA-4 MoAb (D). VLA-4 expression was analyzed in CD34⁺ cells.