CD8+ T‐cell infiltration into human BPH tissues was positively correlated with the expression of CCL5, cyclin D1, and PDE5, whereas in an HFD‐induced prostatic hyperplasia rat model, the activation of the cGMP/PKG signaling by a PDE5‐I could suppress the CD8+ T‐cell infiltration and the CCL5 and cyclin D1 expression. The gene discussed is CCL5; the disease is benign prostatic hyperplasia.