The association of infant leukemia with Down syndrome suggests a unique interaction between the genetics underlying these conditions. Orkin's team is modeling the leukemia in a tissue culture dish, using embryonic stem cells derived from patients with Down syndrome and introducing the mutant form of the GATA1 gene. “The goal is to understand what the original cell is for this leukemia, what the relationship of that cell is to other cells and what genes are involved in mediating the interaction between these disorders,” explains Orkin. The team hopes that by studying this Down syndrome-related leukemia, they will get some broader insights into leukemia genetics. At left: leukemia cells under the microscope.