Microarray studies are disclosing the genes making up specific biochemical events leading to ALL, as well as the changes in gene expression caused by specific treatments. When validated by clinical trials, such information will enable physicians to predict with great accuracy how a specific patient will respond to a particular treatment, and to design treatments that will be the most effective but least toxic.

Breakthroughs in genetic analysis of ALL have also provided evidence that some cases of ALL might be due, in part, to a developmental error or exposure of the fetus to mutagens ”chemicals that cause gene mutations. The recognition that environmental factors might play a role in the development of ALL has prompted large-scale epidemiological studies in the United States and Britain to determine the affect, if any, exposure to chemicals, viruses, bacteria or ionizing radiation.

The authors conclude that genetic studies of leukemic cells will disclose the mechanism of ALL development and lead to the identification of targets for specific treatments. Studies of genes involved in the metabolism and the effects of chemotherapy and environmental agents will also help develop optimal treatment, and may even provide important clues for the cause of leukemia. Together, these advances might one day permit physicians to cure all patients, regardless of the type of ALL they have, and might even lead to ways to prevent this disease.