In the specific case of blood cancer, if the levels of leukaemic cells are below one thousand million, the cancer can’t be detected by a microscope. This means that even in remission, the child’s cancer may relapse due to Minimal Residual Disease (MRD). In 2003, after years of research (and a £3 million contribution from Children with Cancer UK), a new technique emerged that helped doctors predict the risk of recurrence due to MRD. It is thought that this innovation may drive the survival rate for childhood ALL above 90%.