Biology of childhood leukaemia

Integration of conventional morphology and cytogenetics with newer techniques interrogating the genome-wide genetic landscape has gen-erated a detailed insight into the process of leukaemogenesis, as well as the biology of common and rarer leukaemia subtypes in childhood. This has improved diagnosis and classification, risk stratification, out-comes and has provided additional drug targets. Comparative genetic analyses between diagnosis and relapse have established that most relapses are derived from leukaemic clones present at initial diagnosis. Gene mutations acquired at relapse are associated with drug resistance which may explain the occurrence of relapse and lead to future treat-ment adaptations.