Most notable are the lethal GIs between BRCA1/2 and PARP1 (Bryant et al. 2005, Farmer et al. 2005), which led to the use of PARP inhibitors in BRCA1/2-deficient breast (Robson et al. 2017, 2019), ovarian (Mirza et al. 2018), and prostate cancers (Ramakrishnan Geethakumari et al. 2017). This evidence concerns the gene PARP1 and Familial prostate cancer.