Identification of PLZF-RARα direct target genes by ChIP-chip and gene expression arrays. (A) U937T:PLZF-RARα cells were withdrawn from tetracycline for 48 hours and PLZF-RARα expression was assessed by Western blot of whole-cell lysate using PLZF monoclonal antibody (2A9). (B) Loci-specific qPCR using unamplified ChIP samples confirmed PLZF-RARα binding to 100% of putative target promoters compared with uninduced controls (fold enrichment in brackets), a negative control exon region (—). Data are expressed as mean ± SEM of 3 independent experiments (**P < .01). (C) Comparison of PLZF-RARα ChIP dataset (FDR < 0.2, 2/3 replicates; 4916 genes) with gene expression dataset (> 1.5-fold, P < .05; 4472 genes) identified 1672 genes bound and transcriptionally regulated by PLZF-RARα.