The growth rate of the AML1/shITGA6 cells was reduced, and these cells could not be maintained in culture, whereas the AML1/shITGB4 grew at rate similar to the parental UCSD/AML1 control cells, suggesting that the signal transduction of ITGA6 is essential for the maintenance of leukemia cells. The gene discussed is RUNX1; the disease is leukemia.