Although the role of FFAR4 in the development of CCA has not been clarified, in colorectal cancer, FFAR4 can promote angiogenesis and EMT by increasing the secretion of vascular endothelial growth factor (VEGF), IL-8, and prostaglandin E2 (PGE2) [69]. This evidence concerns the gene FFAR4 and cholangiocarcinoma.