To compare the periostin expression in prostate tumor and other conditions of prostate diseases, the TMAs from UCLA which consist of 197 cores of non-tumorous prostate (NT), 140 cores of benign prostatic hyperplasia (BPH), 64 cores of prostate intraepithelial neoplasia (PIN), and 963 cores of CaP were analyzed. The gene discussed is POSTN; the disease is prostate neoplasm.