to try to reverse cartilage degeneration, and to put a short summary on a very long and painful process, essentially it came to naught. Nothing happened. And then about seven years ago, we had a research student from Australia. The nice thing about Australians is that they're habitually used to looking at the world upside down. (Laughter) And so Dan suggested to me, "You know, maybe it isn't a mechanical problem. Maybe it isn't a chemical problem. Maybe it's a stem cell problem." In other words, he had two hypotheses.