PARP1 and cholangiocarcinoma: Investigations utilising cholangiocarcinoma (CCA) cell lines indicate that an elevated burden of DNA damage response (DDR) mutations correlates with heightened sensitivity to both ATR inhibition (AZD6738) and PARP inhibition (olaparib, veliparib, talazoparib), with talazoparib emerging as the most potent agent.