ATR and neoplasm: In light of the evidence that unrepaired DNA damage induced by PARPi expands the anti-tumor activity of the ICI, the therapeutic landscape of DDR-targeting agents has promptly unfolded to include inhibitors of other key mediators implied in DNA replication and repair, such as ATM, ATR, Chk1, Chk2, DNA-PK, and WEE1 [166].