MYB expression controls the MEP fate decision. MYB is differentially expressed in MEPs, MkPs, and ErPs, and MYB downregulation in MEPs promotes megakaryocytic commitment. (A) Quantitative reverse transcriptase-PCR analysis of multiple genes in purified MEP, MkP, and ErP subsets (GAPDH used as an internal control). Knockdown of MYB in CD34⁺ cells showing decreased (B) mRNA and (C) protein expression 24 hours after transduction. (D) Dual Mk/E assay results show increased CFU-Mk as the expense of both CFU-Mk/E and BFU-E when MYB is knocked down (P < .05). Results are presented as average + SD from 3 independent experiments.