Fig. 1.

Frequency and expression of forkhead box P3 (FoxP3) in CD4⁺ T cells in peripheral blood mononuclear cells (PBMC) from untreated chronic lymphocytic leukaemia (CLL) patients and age-matched controls. Frequency of CD4⁺FoxP3⁺ (a) and CD4⁺CD25^hi (b) T cells in untreated CLL patients and age-matched controls. Expression of FoxP3 (c) in CD4⁺CD25⁺ (triangles) and CD4⁺CD25^- (circles) T cells from CLL patients (closed symbols) and controls (open symbols). Solid line represents median. *P < 0·05 using Mann–Whitney U-test.