Higher proportions of CD69⁺ CD4⁺ T cells in FL before SEB stimulation. Activation status, as measured by CD69, before and after SEB stimulation of CD4⁺ T cells from (A) NLN, (B) RLN, (C) FL, and (D) healthy donor PBMCs are shown expressed as the percentage of the total CD4⁺ T cells. Triangles represent values for individual samples, and rectangles represent averages for each tissue type expressed as a percentage of the total CD4⁺ T cells. *P < .05, **P < .01, and ***P < .001 compared with FL, either before or after SEB stimulation.