This conclusion has been confirmed by studies based on breast and ovarian cancer cell lines, where PARP1 increased the PARylation modification of EZH2 during alkylating agent-induced DNA damage or hydrogen peroxide-induced oxidative stress, further inducing the breakdown of the PRC2 complex and degradation of EZH2 (Yamaguchi et al., 2018). Here, PARP1 is linked to ovarian cancer.