Today, we go to a spot that may be one of the most philosophical places in the universe: the thymus, an organ that knows what is you, and what is not you. Its mood may be existential, but its role is practical — the thymus is the biological training ground where the body learns to protect itself from outside invaders (think: bacteria, coronaviruses). But this training is not the humdrum bit of science you might expect. It’s a magical shadowland with dire consequences.

Then, we’ll leave the thymus to visit a team of doctors who are using this organ that protects you as a way to protect someone… else. Their work could change everything.

Special Thanks:

One thousand thanks to Hannah Meyer, Salomé Carcy, Josh Torres, and Cold Spring Harbor Laboratory for showing us a real-life (mouse) thymus for this episode. Special thanks also go to Diane Mathis and Kate Webb.

Further reading:

Wanna do a little light reading? Here’s the immunology textbook Jenni Punt and Sharon Stranford helped write, including a whole section on that funny little thing called AIRE! Kuby Immunology

The science paper that first described what happens inside the thymus as an, “immunological self shadow”.

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