Similar levels of activation and proliferation of CD4 T cells from HICs and HDs in response to anti-CD3 stimulation. (A) Proliferation index of CD4⁺ T cells from HICs and HDs, calculated as the ratio between the cell density before (10⁶ cells/mL) and after 5 days of anti-CD3 stimulation. Each symbol represents one person. Medians for each group are shown. (B) Expression of the CD25 and CD69 activation markers was measured by flow cytometry on the surface of CD4⁺ T cells from HICs and HDs 5 days after stimulation with anti-CD3.