5.

In vivo binding of HNF1 to 7/8 enhancer. ChIP analysis using rabbit HNF1 antibody or rabbit IgG as control and cross-linked Caco2 chromatin, followed by realtime PCR using Taqman® primer and probe sets at the indicated positions of the CFTR locus. A primer/probe set at the a₁-antit-rypsin (AAT) promoter was used as a positive control for HNF1 binding. Each PCR was normalized to 18s rRNA levels and shown relative to an input control. Error bars represent standard error of the mean (n= 4). Lines are used to connect assayed sites and do not necessarily indicate enrichment levels between the sites.