Further, genetic deletion of PU.1 is embryonically lethal, likely due to aberrant myeloid cell production/differentiation [75], whilst conditional deletion during adulthood [76], as well as significant loss in PU.1 expression in rodents carrying hypomorphic spi1 alleles [77] precipitated the development of acute myeloid leukemia. The gene discussed is SPI1; the disease is acute myeloid leukemia.