Frequencies of IFN-γ, IL-17–producing T cells, and CD4⁺Foxp3⁺ T cells during lenalidomide maintenance. Indicated PBMC samples in the x-axes (c indicates cycle; and d, day) were intracellular stained with fluorescent-conjugated antibodies to determine the frequencies of CD4⁺ and CD8⁺ T cells capable of producing IFN-γ (A-B), CD4⁺ T cells capable of producing IL-17 (C), and CD4⁺ T cells expressing Foxp3 (D). To stimulate T cells for cytokine production, PBMCs are incubated for 48 hours with anti-CD3/CD28-coated beads. Solid lines in the scatter plots indicate the mean values; and dotted lines in the graphs, the mean value found in healthy persons (n = 7).