ESR1 and breast cancer: Also included in the present study were Genome-wide protein-DNA interaction data using chromatin immunoprecipitation followed by sequencing (ChIP-seq) for 26 transcription factors (TFs) in MCF-7 cell lines from the ENCODE project, and two independent ChIP-seq datasets for transcription factor ERα each with replicated experiments in the MCF-7 cells20, 21, as well as RNA-seq data across 14 breast cancer cell lines (Table S1).