A model for commitment to the granulocyte and monocyte lineages.

Bipotent GMPs are specified by PU.1 and C/EBPα. Increased levels of C/EBPα expression specify the granulocyte colony-forming unit (CFU-G), a committed granulocytic progenitor. C/EBPα also inhibits monopoiesis via protein-protein interactions mediated by its basic reigon (BR). These interactions occur with proteins that enable JunB transcription or PKC-mediated JunB induction and with additional mediators of monopoiesis, potentially c-Jun, c-Maf, MafB, Egr-1, or ICSBP.