No, I think there are a lot of reasons adding to this. One of the most interesting ones being that patients don't want to wait around for a couple of weeks - if not months in some cases - before they can show a response. With Zytiga, I believe it either works or it doesn't - and the physician and patient know a lot quicker. Putting yourself in the mindset of the patient who wants immediate results. I don't know if I want to wait around to see whether provenge affects my PSA levels. I would want immediate results, or switch to another therapy. It's going to be tough for physicians to convince patients to adopt a 'wait and see' approach. just my 2 cents.