RUNX1 and hematologic disorder: RUNX1, also known as Acute Myeloid Leukemia 1 protein (AML1), is widely considered the master regulator of developmental hematopoiesis because it has a critical function in the specification of the hematopoietic lineage during embryogenesis, while also playing essential roles in postnatal tissue homeostasis and in hematological malignancies.