To further demonstrate the role of CCL5 in the CD8+ T cells promotion of BECs proliferation under low androgen condition, we examined the expression of CD8, CCL5 and PCNA with IHC staining in serial paraffin sections of BPH tissues from 31 patients who were treated with Finasteride for at least six months. The gene discussed is PCNA; the disease is benign prostatic hyperplasia.