SFRP1 and cholangiocarcinoma: The upregulation of EZH2 and downregulation of SFRP1 in the context of O. viverrini infection may play a crucial role in aberrant expression of the Wnt/β-catenin pathway, and it may also be associated with the activation of Wnt/β-catenin signalling and the consequential proliferation of CCA cells.