Cells were lysed and sonicated leading to a DNA average size of 200bp. Protein G dynabeads were pre-incubated with 5μg of ER alpha (sc-543) or FOXA1 (ab5089) with pre cleared chromatin. The complexes were reverse cross-linked and DNA was purified. ChIP-seq libraries were prepared using 10 ng of DNA and Illumina's TruSeq ChIP sample prep.Libraries were validated using the Agient Technologies 2100 Bioanalyzer and Qubit high sensitivity assay.