PARP1 and cancer: Additionally, recent study has shown that CRISPR-based target discovery screening identified DNA polymerase beta (POLB) as a synergistic enhancer of the synthetic lethality between PARP and BRCA1/2, supporting POLB as a promising therapeutic target for improving antitumor responses to PARP inhibitors in homologous recombination–deficient cancers [58, 59].