MTOR and cholangiocarcinoma: Surprisingly, L-ascorbic acid has been reported to induce cytotoxicity in CCA cells by generating intracellular reactive oxygen species (ROS), and subsequently DNA damage, ATP depletion, and inhibition of the “mammalian target of rapamycin” (mTOR) survival pathway, which results in a synergistic effect with cisplatin both in vitro and in vivo.