A cancer therapy that uses genetically engineered immune cells, called CAR T-cells, has kept a person free of a potentially fatal nerve tumour for a record-breaking 18 years. “This is, to my knowledge, the longest-lasting complete remission in a patient who received CAR T-cell therapy,” says Karin Straathof at University College London, who wasn’t involved in the treatment. “This patient is cured,” she says. Doctors use CAR T-cell therapy to treat some kinds of blood cancer, like leukaemia. To do this, they collect a sample of T-cells, which form part of the immune system, from a patient’s blood and genetically engineer them to target and kill cancer cells. They then infuse the modified cells back into the body. In 2022, a follow-up study found that this approach had put two people with leukaemia into remission for around 11 years, a record at the time.