Gfi1 is present on Gfi1 target genes in monocytes. (A) ChIP analysis on sonicated chromatin of primary monocytes was performed using an α-Gfi1 antibody or a goat–IgG antibody as control (n = 2). Quantitative PCR was used to measure the amount of immunoprecipitated promoter, which was compared with the control genomic sequence of albumin. The percentage of recovery of the ChIP promoters was plotted as the fold increase over the percentage of recovery of albumin. Error bars indicate standard deviation. (B) The mRNA levels of Gfi1-regulated genes were measured using quantitative RT-PCR on mRNA from monocytes (n = 5) and granulocytes (n = 6). Expression in granulocytes was set at 100%. (C) ELA2 (top panel) and C/EBPα (bottom panel) quantitative RT-PCR was performed on RNA samples of HL60 cells during PMA- or ATRA-induced differentiation (n = 2). ELA2 and C/EBPα expression levels in untreated HL60 and U937 cells were set at 100% and values were normalized for β-actin expression. (D) ELA2, C/EBPα, and Gfi1 mRNA expression was measured using quantitative RT-PCR and were normalized for 18S rRNA expression. The levels in untreated cells (−MG132) were set at 100% and compared with MG132-treated HL60 cells.