PDE5A and benign prostatic hyperplasia: Our previous studies have shown that induction of CCL5 secretion by infiltrating CD8+ T cells promoted BEC proliferation in low androgen conditions.10 In the present study, we examined the infiltration of CD8+ T cells and expression of CCL5, CCND1, and PDE5 in BPH tissues from 16 patients treated or 18 patients not with finasteride for at least 6 months.