Increased levels of PARP1 have also been observed in breast cancer (Siraj et al., 2018), gastric cancer (Afzal et al., 2019), ovarian cancer (Kummar et al., 2012), pancreatic cancer (Xu et al., 2019), and liver cancer (Li et al., 2017) The dependence of prostate cancer on PARP1 activity was shown in the reduction of AR to PARP1 inhibition (Espinoza, 2013). Here, PARP1 is linked to breast cancer.