The degree of HO-1 expression in the nuclei of PCa cells was significantly higher than in the nuclei of prostate epithelial cells in non-neoplastic surrounding parenchyma (30 of 85, 35%) or BPH (9 of 39, 23%) (χ2, P<0.0001) (Table 2). This evidence concerns the gene HMOX1 and benign prostatic hyperplasia.