LIG4 and ovarian cancer: To verify the RNA-Seq results, 9 genes involved in regulation of DNA repair and apoptosis (BRCA2, EXO1, FANCD2, LIG4, XRCC4, BAX, BCL2, CASP7, and TRADD) were selected and analyzed with quantitative reverse-transcription PCR (RT-qPCR) using OVCAR8 ovarian cancer and MDA-MB-231 breast cancer cells.