IDH1 and cholangiocarcinoma: In addition, since IDH1 mutations can affect the mechanism of double-stranded DNA damage repair [154], several ongoing trials are also evaluating in mIDH1-CCA patients the efficacy of poly(ADP-ribose) polymerase (PARP) inhibitors such as olaparib (NCT03212274), olaparib plus the ATR inhibitor ceralasertib (NCT03878095), and olaparib plus durvalumab (NCT03991832).