The war that’s constantly happening inside of you.
Everyone knows about your immune system but the sheer complexity of it is amazing. Like, your body has neutrophils which are like the generic white blood cell that constantly goes around your blood vessels seeking out foreign objects, but did you know there are cells called macrophages which are like way better neutrophils in the fact that neutrophils mostly swallow bacteria to kill them, macrophages do this too except they can swallow close to 100.
You have stuff like dendritic cells whose main goal is to be an early warning system, they swallow an invader then carry a piece of it back to T cells to activate them. Once they’re activated, T cells swarm that specific invader and kill anything that has that antigen.
I didn’t even name close to all of the cells that are doing constant battle inside of you 24/7 365 days a year. So next time you have the flu or an infection, think of the little guys inside you who gladly fight the good fight.