FL B cells with dual TNFRSF14 aberrations stimulate allogeneic T-cell activation more effectively than WT FL B cells. (A-B) Proportion of CD4⁺ and CD8⁺ T cells expressing the activation marker CD25 after primary (A; n = 7) and secondary (B; n = 5) allogeneic cocultures with WT FL B cells or FL B cells with dual TNFRSF14 aberrations. Horizontal bars and adjacent numbers represent median values and P values are for 2-tailed paired Student t tests. (C) Proportion of CD4⁺ T cells expressing the CD25^hiCD127^lo regulatory T-cell surface phenotype or (D) FOXP3 after primary (n = 4) and secondary (n = 4) allogeneic cocultures with WT FL B cells or FL B cells with dual TNFRSF14 aberrations. Mean values are shown and error bars represent standard deviation. P values are for 2-tailed paired Student t tests.