The ones Teresa is handling in this Cambridge laboratory are mini bile ducts, thin tubes that carry bile from the liver to the small intestine to help with digestion.

Teresa also has gut organoids in the incubator, while down the corridor a different team is developing brain organoids.

In fact, around the world, miniatures of everything from lungs to kidneys are being coaxed gently to life. And because they function just as organs do, they are perfect for research.