Intracellular cytokine production of expanded CIK cells from CML patients. CIK cells from different patients on various days of culture were stimulated with PMA and ionomycin for 4 hours then stained with surface antibodies against CD3 (PCP) and CD56 (PE), followed by permeabilization and intracellular staining with FITC-labeled antibodies against TNF-, IFN-γ, IL-2, and IL-4. The percentage of CD3⁺56⁺ cells (light shaded bars) and CD3⁺56⁻ cells (dark bars) expressing TNF-, IFN-γ, IL-2, and IL-4 is shown.