RUNX1 and acute promyelocytic leukemia: For example, the AML1‐ETO fusion protein generated by t(8;21) has the capability to repress the expression of GATA‐1.37 Our findings emphasize the importance of LMO2 in erythropoiesis and reveal a previously unidentified mechanism of defective erythropoiesis in APL, by which PML‐RARα specifically transrepressed LMO2, and thereby interfered with erythroid differentiation.