Our finding is consistent with an earlier study focusing on IAP expressions in various stages of prostate cancer tissues, which demonstrated that increased expression of IAP (cIAP-1, cIAP-2, XIAP and survivin was an early event in prostate cancer and did not correlate with Gleason grade [39] Our data and previous studies suggested that BIRC6, like other IAP family members, is functionally more critical at an early stage than at a late stage of prostate cancer. This evidence concerns the gene XIAP and prostate cancer.