Nuclei were isolated and treated with micrococcal nuclease (2,000 U/ul) for 25 minutes at 37 degrees to digest chromatin. Nuclie were briefly sonicated, clarifed and then TCF7L1-DNA complexes were isolated by immunoprecipitation. Illumina sequencing libraries were constructed using the Bioo Scientific NEXTflex Rapid DNA-Seq kit and NEXTflex DNA barcodes (Bioo Scientific Corporation, Austin TX). Ten nanograms of input DNA was taken into end repair, adenylation and adapter ligation reactions. The adapter ligated product was cleaned up without library size selection using Agencourt AMPure XP beads (Beckman Coulter, Inc. Brea, CA). The cleaned ligated DNA was amplified by 15 PCR cycles to enrich for adapter ligated products. The amplified PCR product was cleaned by AMPure XP beads and the library was size selected using the Blue Pippin 2% agarose gel with broad range settings (206bp – 561bp) (Sage Science, Inc. Beverly, MA). The libraries were quantified by Kapa qPCR (Kapa Biosystems, Inc. Wilmington, MA). The libraries were denatured and diluted to 13pM for onboard clustering on the Illumina HiSeq 2500 (Illumina Inc., San Diego, CA) using rapid run mode and SR50 chemistry. The HiSeq 2500 real time analysis software was version 220.127.116.11 and the HiSeq control software version was 18.104.22.168.