Therefore, the present study was undertaken to investigate PARP1 transcriptional regulation from genetic (BRCA1 mutation) and epigenetic (promoter methylation, histone modifications and transcription factor binding) aspects, and to provide novel insight into epigenetic change-mediated abnormal PARP1 expression in BRCA1-mutated ovarian cancer progression. The gene discussed is BRCA1; the disease is ovarian cancer.