Representative dot-plots of intracellular cytokine expression as evaluated by flow cytometry. Samples from the same patient, in this case a responder, were analyzed before rituximab therapy and 3 months after the first rituximab infusion. The sample of a control subject has been reported for comparison. In the upper plots, CD4⁺ cells were sorted into Th1 and Th2 subsets according to the expression of either IFN-γ or IL-4. In the lower plots, CD8⁺ cells were sorted into Tc1 and Tc2 subsets according to the expression of either IFN-γ or IL-4. At 3 months, the patient sample showed an increase of the percentage of Th2 and Tc2 cells compared with baseline, with values very similar to the control sample.