Besides, the overexpression of HMGB3 significantly reduced the protein levels of cleaved caspase 3 and cleaved PARP1 following olaparib treatment, whereas ovarian cancer cells with HMGB3 knockdown showed increased levels of cleaved caspase 3 and cleaved PARP1 (Fig. 3A–D). This evidence concerns the gene PARP1 and ovarian cancer.