A teenager, who was suffering from an incurable cancer, is now free from the disease, thanks to a revolutionary gene therapy called Base editing. The new therapy holds a huge promise for lakhs of people worldwide who suffer from an incurable form of blood cancer called T-cell acute lymphoblastic leukaemia. Doctors at the Great Ormond Street Hospital in the UK decided to try out the new treatment after all other therapies including chemotherapy and bone-marrow transplant failed.