The supplementary methods section details the procedures used for antibody preparation, chromatin immunoprecipitation (ChIP), and data analysis in a study focusing on transcription factor binding and gene regulation. Antibodies against various transcription factors, including androgen receptor (AR), ERG, FLI1, ELF1, SPI1, and EWS, were obtained from different suppliers. ChIP experiments were conducted on several cell lines, involving cross-linking, lysis, sonication, and immunoprecipitation steps. The ChIP DNA was quantified and prepared for sequencing, with a focus on ensuring library complexity. Massively parallel sequencing was performed using Illumina/Solexa technology, and data analysis included peak calling, motif enrichment, and validation using qPCR. The study also compared the results with previously published data and used siRNA knockdown to analyze gene expression. The supplementary tables and figures provide additional details on the experimental procedures, antibody clones, binding profiles, and primer sequences.The supplementary methods section details the procedures used for antibody preparation, chromatin immunoprecipitation (ChIP), and data analysis in a study focusing on transcription factor binding and gene regulation. Antibodies against various transcription factors, including androgen receptor (AR), ERG, FLI1, ELF1, SPI1, and EWS, were obtained from different suppliers. ChIP experiments were conducted on several cell lines, involving cross-linking, lysis, sonication, and immunoprecipitation steps. The ChIP DNA was quantified and prepared for sequencing, with a focus on ensuring library complexity. Massively parallel sequencing was performed using Illumina/Solexa technology, and data analysis included peak calling, motif enrichment, and validation using qPCR. The study also compared the results with previously published data and used siRNA knockdown to analyze gene expression. The supplementary tables and figures provide additional details on the experimental procedures, antibody clones, binding profiles, and primer sequences.