Conserved CD40L induction on normal polyclonal CD4⁺CD7⁺ cells of patients with SzS. (A) PBMCs were activated with anti-CD3. After 6 hours, cells were immunostained for CD40L, CD4, and CD7 and analyzed by flow cytometry. Dot plots show CD4 and CD7 expression for a healthy donor and patient S1 with a CD4⁺CD7^-tumor (left panels). The percentage of labeled cells for each quadrant is indicated in the upper right quadrant. Histograms representing CD40Lexpression on unstimulated (thin lines) and anti-CD3-stimulated (thick lines) gated CD4⁺CD7⁺ T cells are shown (right panel). (B) CD4⁺CD7⁺ nontumor T cells were analyzed as in panel A for CD40L expression upon anti-CD3 stimulation. Percentage of CD40L⁺ cells obtained in the CD4⁺CD7⁺ T-cell fraction of healthy donors (n = 13) and patients with SzS (n = 3) is shown. Minimum and maximum values obtained with healthy donors are indicated.