CD147 expression levels divide CD4⁺ FoxP3⁻ and FoxP3⁺ T cells into 3 functionally different subsets with different levels of cytokine production. CD4⁺FoxP3⁻ (A) or CD4⁺FoxP3⁺ (B) T cells were analyzed for their capacity to produce cytokines (IL-2, TNF-α, IFN-γ, IL-17, and IL-10) and the expression of CTLA-4 after stimulation with PMA and ionomycin and stratified by their CD147 expression. Percent cytokine producing cells are shown from one representative of 4 independent experiments. Histograms are shown for CTLA-4 expression at different levels of CD147 expression.