A schematic diagram of the distal 5′ flank of the ₂ integrin gene. Identification of numerous potential binding sites for ubiquitous as well as megakaryocyte-specific transcription factors are shown. Three distinct regions are responsible for ₂ integrin gene expression in cells with megakaryocytic origin. These include a core promoter between bp −30 and −92, a silencer/repressor between bp −92 and −351, and megakaryocyte-specific enhancers in the distal 5′ flank between bp −1426 and −1655. The megakaryocyte-specific enhancer is underlined and bracketed. Data from Zutter et al.14