ADGRB1 and intrahepatic cholangiocarcinoma: ADGRB1 has been reported to prevent MDM2‐mediated p53 polyubiquitination, consequently activating p53 signaling pathway in medulloblastoma.[8] In order to investigate the role of ADGRB1 in ICC via circUGP2, we performed coimmunoprecipitation (co‐IP) assays.