Figure 1 illustrates PARP inhibitor resistance mechanisms and rationale for therapy combinations exploiting these mechanisms. Figure 2 illustrates the rationale for combining PARP inhibitors with DNA damaging agents (Figure 2A) and immunotherapy (Figure 2B). Tables 1 and 2 summarizes published and ongoing phase II-III studies of PARP combinations for ovarian cancer. Here, PARP1 is linked to ovarian cancer.