Activated T cells from patients with CLL express CD178 and TRAIL. CD4⁺ T cells from patients with CLL were isolated and activated as described in “Materials and methods.” Surface expression of TRAIL or CD178 on CD4⁺ T cells was analyzed before (top row) or after (bottom row) CD3/CD28 activation. (C) The shaded histograms represent TRAIL (left column) or CD178 (right column) expression. Isotype-matched controls mAb staining are given as solid lines, whereas autofluorescence is provided as dashed lines.