EKLF knockdown increases FLI-1 occupancy at the Gp1b, GpIX, and Fli-1 megakaryocytic gene promoters. ChIP experiments were performed as described in Figure 2 (the same chromatin samples were used) using either anti–FLI-1 (A) or anti–GATA-1 (B) antibodies. Results are expressed as relative proportions of immunoprecipitated DNA (ratios of immunoprecipitated versus input DNA) standardized to the ratio obtained for the Gp1b promoter in untreated cells (means and standard deviations from 3 independent cultures). Significant (P < .05; paired Student test) doxycycline effects are indicated by asterisks (NS indicates nonsignificant). Insert corresponds to the Western blot analysis of FLI-1, EKLF, GATA-1, and GRB2 present in total protein extracts from the 4D7 cells used for the ChIP experiments (stars correspond to unspecific bands). Percentages in brackets indicate the change of FLI-1, EKLF, and GATA-1 levels induced by doxycycline as estimated by densitometry (relative values standardized to GRB2 and expressed as percentage of values without doxycycline).