To evaluate the pathogenic role of this indigenous bacterium in the development of prostate cancer, we examined radical prostatectomy samples obtained from patients with or without prostate cancer by immunohistochemistry with the novel antibody to P. acnes and an antibody to NF-κB, which was used to determine a possible correlation between P. acnes infection and nuclear NF-κB expression in prostate glands. The gene discussed is NFKB1; the disease is prostate cancer.