Expression of p-glycoprotein in case 4. Immunofluorescent flow cytometric analysis of p-glycoprotein on leukemic cells from the patient (case 4) was performed. Cells were stained with anti–p-glycoprotein monoclonal antibody JSB-1 ( — ) followed by PE-conjugated goat anti-mouse IgG as a secondary antibody. As a negative control (- - - - - - -), only secondary antibody was used.