YY1 and cholangiocarcinoma: A recent study reported that circ-CCAC1, which is expressed at a high level in biliary exosomes of patients with cholangiocarcinoma, can enhance the transcription of CAMLG in cholangiocarcinoma cells by absorbing miR-514a-5p and upregulating YY1, and CAMLG promotes the progression of the tumour cells.