A-C. Luciferase assays performed with various lengths of the human pIII promoters (A), the pIII promoters in the presence of PU.1 siRNA (open bar) or control siRNA (closed bar) (B), and the mutant promoters lacking Ets-motif(s) (C). Data represent means ± SEMs of three independent experiments. Each experiment was performed with triplicate samples. *, p < 0.05.