 Well, dengue is actually one of the world's most common mosquito-spread diseases. And in 75% of the cases, the people who get infected don't actually get very sick. Well, that's good. Yeah, that's good. But in a quarter of those cases, they do. And those symptoms can be pretty awful. People can get high fevers, debilitating headaches, joint pains. And in some severe cases, it can cause people's blood vessels to leak, and it can lead to shock and even death.