The patient known as P2 is just 18 years old, but he has been receiving monthly blood transfusions since the age of 3. P2 has a genetic disorder called beta-thalassaemia. Thanks to a double whammy of faulty genes, he can’t produce working versions of haemoglobin, the protein that allows red blood cells to carry oxygen around the body. Regular transfusions were the only things that kept him alive but for the last 21 months, he hasn’t needed them.

An international team of scientists have managed to partially correct his genetic faults, granting him his independence. It’s a major victory for gene therapy, the act of editing faulty genes within living cells in order to treat diseases.

The haemoglobin protein