This improvement in medium disease-free survival is probably a result of sustained early cell kill, and UKALL VIII has enabled us to define risk categories requiring even further continuous intensification, as now introduced in MRC UKALL X. Thanks to the greater availability of blood products, for example, the rational use of antibiotics and the development of expertise amongst nurses and doctors, such sustained therapy can now be delivered on a multi-centre basis, but only in experienced centres. The monitoring and removal of morbidity are essential if the advantages of this more sustained chemotherapy are to be realised. All elements of therapy require controlling and patients, parents and, above all, doctors must comply with protocol requirements in order to build further upon these initial promising results.