The expression of homeobox genes during megakaryocytopoiesis. The expression levels of homeobox genes in human megakaryocytes were evaluated. The cultured cells were harvested, and the total RNAs were isolated. RT-PCR was performed with specific primers for PF4, Meis1, Pbx1a, Pbx1b, Pbx2, NF-E2p45, or HPRT (as a control).