Cancer is the leading cause of death due to disease among children aged 0-14. Acute lymphoblastic leukemia is the most frequent form of cancer. Despite what is known about the leukemic process, there remains much to be learned about the molecular basis of this disease. Analysis of target genes known to be involved in the leukemic process would greatly improve our understanding of this disorder. During recent years, we have identified a region on human chromosome 12 containing a tumour suppressor (anti-cancer) gene. ETV6, one of the genes at this region, encodes a transcription factor, which is absent in many children with leukemia. We propose a research strategy that incorporates the study of DNA (genetic information), RNA (genetic message) and proteins (function) in order to further understand the role of ETV6 in the development of leukemia. These findings will then be used to develop more appropriate and efficient diagnostic and treatment tools for children living with leukemia.