Recently, in attempts to provide a vaccine against prostate cancer or HIV, BCG cell wall skeleton (BCG-CWS) (30) or Ag85B of mycobacteria (known as an immunogenic protein for Th1 development) (32) were shown to enhance the induction of CTL responses against prostate-specific antigen (PSA) or HIV gp120, respectively. This evidence concerns the gene KLK3 and prostate cancer.