 So the immune system, you might be like, dude, the immune system just protects the body from going out of homeostasis. The fact is, the immune system actually often results in, the immune system response often results in an effect on a regulated variable of the extracellular fluid. So the immune system often pushes your body out of homeostasis. But it's worth it. It's like, do I want to be tired from running away from the bear, or do I want to be eaten by the bear? Do I want to be dealing with my pH levels being wonkadoozy or because I'm dealing with an invasion of some evil thing, or do I want to be invaded by that evil thing and die? It really isn't much of a choice. You go out of homeostasis in order for the immune system to function, and there's links here. And so I'm going to just take a second to share some of these connections with you. And most obviously, the immune system often changes a set point, changes the set point of a regulated variable. And so it can adjust. And the first thing you should think of is body temperature. Fever, the set point gets changed. But in the middle of an immune response, glucose levels can be adjusted so that you actually have a different amount of glucose, either more or less, in your system. And so you're changing the actual homeostatic level that you would expect from a regulated variable. Now these are ways that the immune system affects homeostasis and these aren't good, but they're just reality. But it's worth it. So there are connections here. The immune response can affect the sensitivity of a target. So a target can become more or less susceptible or more or less sensitive to a regulated variable or a message about how to maintain a regulated variable. And if you are changing the sensitivity to the target, this can have outcomes. This can have consequences for your system. And you can also change the sensitivity of the integrators. And there is a really interesting article that is somewhere in this pile of madness and I'll try to remember to post it to Canvas so you guys can check out this article if you're interested in exploring this concept a little bit more. It's sort of technical. It compares homeostasis to these engineering systems which is talking about plants and stocks and flows and there's like a whole another level of vocabulary that goes into it that's not familiar to me at all but it might be familiar to you and it was an interesting perspective on the immune system. Basically the immune system can throw, can affect a homeostatic system and that's the link. It's worth it though. It's worth it to protect yourself against the bad guys. Immune system, you did it. Oh my gosh, I love the immune system and I love kidneys and that's what's coming next.