Similarly, ATM is closely associated with the repair of double‐stranded DNA breaks, and research shows that inhibition of the transcription factor ATM in cholangiocarcinoma caused a potent response to DNA damaging agents, enhancing their cytotoxic effect, particularly in RMCC1 and HuCCA1 cell lines, deficient in p53 [71]. This evidence concerns the gene ATM and cholangiocarcinoma.