IκBζ expression in CD56⁺ and CD56⁻ cells. Human lymphocytes were isolated from PBMCs after CD14 depletion followed by positive selection for CD56⁺ cells. Cells were stimulated (5 × 10⁶ cells) with recombinant IL-12 and IL-18 (10 ng/mL each) for 6 hours and 24 hours. Protein normalized cell lysates were immunoblotted for IκBζ and actin. Results are representative of 2 independent experiments. *Nonspecific band (IκBζ blot), which confirms equal protein loading as the actin expression is very high.