Luciferase-reporter studies on MYL9 promoter in PMA-treated HEL cells. Luciferase activity with Wt construct (□) and constructs with RUNX1 sites I-IV mutated (■) are shown. Mutation of any of the 4 RUNX1 sites resulted in a decrease in reporter activity, suggesting that all 4 RUNX1 sites are functional. A truncated construct (−591/+4) with no RUNX1 sites is also shown. The means ± SE are shown for 3 independent experiments in triplicates.