The expression of USF1 and USF2 during megakaryocytic differentiation. The expression levels of USF1 and USF2 genes in human megakaryocytes were evaluated by RT-PCR. Purified CD34⁺ cells were differentiated by TPO. The cultured cells were collected after 0, 4, or 10 days of differentiation, and total RNAs were isolated. RT-PCR was performed with specific primers for USF1 and USF2, PF4, and GPIIb.