In the liver, as in many other organs, TGF-β acts as a tumour suppressor in the early stages of tumour development, while in advanced stages it exerts tumour-promoting actions.8 In addition, TGF-β helps to generate an advantageous TME by activating CAF, inducing angiogenesis and promoting immune suppression and evasion.8 Despite being thoroughly investigated in some cancers such as hepatocellular carcinoma (HCC)9 and pancreatic cancer,10 these processes are still understudied in CCA.11 This evidence concerns the gene TGFB1 and cholangiocarcinoma.