Intracellular IFN-γ expression. (A) Intracellular IFN-γ expression in CD3⁺CD25⁺ or CD3⁺CD4⁺CD25⁺ cells stimulated with PHA in the presence of different concentrations of bortezomib (1 of 5 similar experiments is shown). (B) Box plot of CD4⁺CD25⁺IFN⁺ cells for the different doses of bortezomib for the 5 samples analyzed. Error bars indicate 95% confidence intervals.