Chopped and diced: Dicer1 deletion generates myeloid dysplasia.

Gene targeting studies revealed that Dicer1 is required for murine embryogenesis.In this issue of Blood, Alemdehy and colleagues examine deletion of Dicer1 in myeloid progenitor cells using a conditional Cebpa-Cre allele. They show that deletion of Dicer1 is required for viability and that Dicer1 regulates steps of neutrophil maturation.