GEPIA analysis of the TCGA-CHOL dataset showed no difference in PDGFRA expression between normal and tumor tissues, while PDGFRB was significantly upregulated in tumors, suggesting that PDGFR-β is the major functional receptor of PDGF-BB in CCA (Supplementary Fig. 3A-B). This evidence concerns the gene PDGFRA and cholangiocarcinoma.