Fig. 2From: Homologous recombination proficiency in ovarian and breast cancer patientsPARP inhibitors (PARPi) and mechanisms of PARPi resistance. A PARPs travel to DNA single-strand breaks. B PARP inhibitors can trap the enzyme and prevent it from properly functioning. C-E Potential mechanisms of resistance to PARPi therapy. C PARPi may be blocked, D effluxed, or E reversion of BRCA1/2 mutationsBack to article page