Regarding this question and answer from Mindy's Blog: CFS Central: In your prostate-cancer study, XMRV is present in malignant prostatic epithelium and is associated with prostate cancer, especially high-grade tumors, you found 4 percent of healthy controls with evidence of XMRV. If youre finding a background rate in controls in your prostate-cancer studies, why do you think you didnt find a background rate in CFS patients and controls? Singh: Not entirely sure, but there were different assays (e.g. immunohistochemistry) and different sample types (blood vs prostate tissue). This is probably obvious to someone else, but not to me. My question is: Why didn't Singh use the same assay she used in her prostate cancer study? Was it an assay that would only work for tissue samples and not for blood samples? Can someone answer this question for me please? Thank you.