We’ve got a thymus plush now! This incredible gland is an important part of the immune system, it works hardest in young bodies and declines after puberty. The thymus, located inside your chest, nestled between your lungs, provides a place for T-cells to mature before they go out and kick some virus, bacteria or parasite booty. Thanks, Thymus! Also, if you’ve ever eaten sweetbreads, that’s the (not human) thymus you’re munching on.