Coordination of erythropoiesis by c-Myb. c-Myb has a dual role as a regulator of erythroid development. Both in uncommitted/early stages (CD71^–/low) and in later stages (CFU-E/erythroblast—CD71⁺TER119^–/low), high levels of c-Myb are required for an efficient response of progenitors to erythropoietic stimuli and progression to later stages. c-Myb is indirectly involved in the down-regulation of GATA-2, Runx1, PU.1, Fli-1, and CD45, a process that is a prerequisite for terminal differentiation. At later stages of erythropoiesis, high levels of c-Myb allow the cells to undergo terminal cell divisions. Finally, c-Myb maintains high levels of c-Kit expression on erythroid progenitors, thereby rendering them responsive to external signals regulating proliferation and differentiation.