TGF-β signalling plays a central role in carcinogenesis by modulating key events both in tumour cells and the TME.8 Therefore, to exploit the potential of TGF-β as a therapeutic target in iCCA, it is essential to understand the specific actions that TGF-β promotes in the different cells conforming the tumour. This evidence concerns the gene TGFB1 and infantile convulsions and choreoathetosis.