One of the great success stories of modern medicine is undoubtedly the remarkable improvement in outcome for childhood cancer, achieved through the work of the co-operative groups enrolling patients in randomised controlled trials. In 1965, survival was almost zero; now 5-year survival rates exceed 80% in high-income countries. The lessons learned in the care of patients with the most common malignancy in childhood – acute lymphoblastic leukaemia – have been used in all other cancers of childhood and more recently in the management of adults. These lessons can be broadly applied in medical practice, because elements of laboratory science in all branches of pathology, as well as a deep understanding of biochemistry, physiology, pharmacology, genetics and molecular science, run through this story. Far from being a sad area of practice, paediatric haematology and oncology remains the champion of embedded clinical and translational research, diagnosis from bench to bedside and lifelong multidisciplinary management of the child and their family.