More ADO about IDO: GVHD.

apoptosis. As the authors note, the phenotypic features of C/EBP -deficient granulopoiesis resemble those of a myelodysplastic syndrome. Because C/EBP mutations and/or dysfunction are known to be involved in the pathogenesis of acute myeloid leukemia (AML), it is possible that inactivation of other C/EBP proteins such as C/EBP play a role in myeloid disorders (MDSs) as well. For example, C/EBP is frequently inactivated by promoter methylation in AML,3 and it is possible that C/EBP function might be altered in myeloid malignancies and MDSs. Also, the findings by Akagi et al clearly show that a normal white blood cell count in a genetic mouse model can, under steady-state conditions, conceal an important function of the gene in hematopoiesis. The critical importance of granulopoiesis and granulocyte function in hematology and clinical medicine is obvious, and we have made a lot of progress in deciphering its mechanisms. Nonetheless, tools to more effectively and specifically manipulate granulocyte functions and productions are necessary. The findings presented by Akagi and colleagues might help to design new strategies for overcoming neutropenia and granulocyte dysfunction. Conflict-of-interest disclosure: The authors declare no competing financial interests. ■