Tcf4 associates with the promoter of miR-181s. (A) Predicted Tcf4 binding sites in the promoter region of the miR-181a-2/miR-181b-2 gene. (B) PCR amplicons for ChIP assay were designed within 200-bp windows in the ~700-bp upstream of the transcription start site (amplicon U), and in the ~500-bp downstream of transcription start site (amplicon D). (C) PCR analysis of Tcf4 chromatin immunoprecipitate. Actin chromatin immunoprecipitate was used as negative control. PCR products were run on a 3.0% agarose gel.