Here, we show that IGF-1R blockade results in HR impairment and sensitization to PARP inhibition in ovarian and breast cancer cells without BRCA mutations, providing a rationale to combine IGF-1R and PARP inhibitors in this indication and providing new opportunities for the development of targeted personalized cancer therapy, expanding the number of patients that could benefit from PARP inhibitors. The gene discussed is IGF1R; the disease is cancer.