Helen, I guess my only comment at this point, is that we do not know all the mechanisms by which someone might contract HPV, though clearly sexual contact of all types, and if we are going to be completely graphic and candid here, that includes, conventional, oral and anal that are well demonstrated. HPV's impact on cancers may even extend outside of the world of the contact areas, and there is very preliminary evidence finding it in cancers in other areas of the body. Merck in their vacine program is also looking at the anal cancer world and of course besides hetrosexuals, that includes the homosexual male community. HPV is a problem of significance the degree of which is still being discovered.