SFRP1 and cholangiocarcinoma: Wnt proteins initiate intracellular signalling pathways by binding to frizzled (FZ) receptors and coreceptors, thus revealing their cellular effects [138], and notably, in the case of Ov-CCA, it has been observed that SFRP1 is downregulated from hypermethylation, supporting the finding of EZH2 overexpression leading to decreased SFRP1.