The percentages of CCR5-expressing CD3+ cells and CD4+ T cells in TB-PEs were significantly higher than those in malignant PEs (6.57%±1.02% vs 2.47%±0.36%, n = 6, p<0.05; 5.30%±0.84% vs 1.67%±0.25%, n = 6, p<0.05). Here, CD4 is linked to tuberculosis.