When I mentioned stage four, if those cells have left that village and then got on the highways, the lymph node system, the blood system, kind of gotten off the exit and gone into other organs. You can't do surgery now for the most part. Because sure, you could take out what you see, but you know, much fewer cells went on those journeys around the body and are circulating. And so if you took it all out and did those surgeries, it's very difficult -- not difficult, impossible, to treat the stuff that's circulated to get there. And that's why stage four for the most part is incurable, but there are some exceptions. And we're going to talk about that in a different video.