In addition to synthetic lethality, PARP inhibitors have been proven to regulate the TME by activating immune pathways and up-regulating the expression of PD-L1 in cancer cells, which enhances the efficacy of PD-L1/PD-1 blockade (Pantelidou et al. 2019; Kim et al. 2020; Shen et al. 2019; Peyraud and Italiano 2020). Here, CD274 is linked to cancer.