Anti-c-kit and anti-α₄ staining of BM and PB from control (untreated) and Ptx-mobilized animals. Following Ptx treatment, down-regulation of α₄-integrin expression in c-kit⁺ cells from BM and PB is seen. The 4 FACS dot plots on the left show control (upper panels) and Ptx-treated (lower panels) BM and PB. The histograms in the 2 panels on the right show α₄ expression in kit⁺ cells from BM and PB of controls (shaded) and Ptx-treated animals (solid lines). The numbers over the cell peaks indicate the MFIs of control and Ptx-treated (2 peaks) BM and PB cells (one peak).