To verify the PARP1 contribution to the transcription of genes that are concomitantly controlled by BRG1–EP300 complexes (described by Sobczak et al. [12]), we targeted PARP1 with siRNA in both studied breast cancer cell lines and measured the mRNA levels of the selected genes representing two gene ontologies (Figure 3A). The gene discussed is EP300; the disease is breast carcinoma.