PPFIBP2 and cholangiocarcinoma: To test tumour growth in vivo, a subcutaneous xenograft mouse model was established to observe the role of HPR in cholangiocarcinoma, and the results supported that tumour volume was increased in the CCLP1-HPR group compared with that in the control group and that the tumour volume was decreased in mice inoculated with QBC-939-shHPR cells (Fig. 7c, d).