 Those are asymptomatic transmission, where you don't have a fever, you don't have sweats and that sort of thing, so that's number one, and rapid human-to-human transmission. Every frontline doctor in the world who's hearing about a new virus jumping from an animal in a market is going to think, okay, it's bad for that patient in the room I'm about to go into, but I'm not going to worry about human-to-human spread.