Thank you for addressing a very interesting and important question. As you mention, our study reports on the safety and feasibility of platelet rich plasma (PRP) in the treatment of common urologic conditions, including erectile dysfunction, Peyronie's disease, and stress urinary incontinence. None of our patients, however, had a history of cancer, so we cannot say whether this therapy is safe in those types of patients as it concerns tumorigenicity and recurrence. We are currently working with Dr. John Jackson's Lab at the Wake Forest Institute for Regenerative Medicine to study stem cell therapy in the cavernous nerve crush model as well as PRP and its associated growth factors that may play a role in tissue regeneration. We do not, however, have any data on the implication of these therapies in animals or humans with a history of cancer. We certainly agree that the role of PRP in nerve regeneration after tumor excision deserves further experimental investigation and we thank you for discussing this very salient point.