 So now, I mean, people don't know this, but now you know this. How do we know this? Because we've had a zillion people check their blood oxygen levels, and then I ask them, how do you feel? What did you do today? What did you eat today? How did you sleep today? I get a zillion questions, and they'll tell me all this stuff. And over the years of doing this now, a pattern has emerged, and that pattern is blood oxygen turns out to be really important for you to be functional.