These patients usually demonstrate severe venous cancer invasion, advanced tumour stage and shorter survival.17 Recent studies reported that SOX9-positive HCC cells exhibit liver cancer stem cell (CSC)-like features, and that SOX9 in cancer cells confers self-renewal and tumourigenicity by promoting symmetrical cell division.17,18 To date, only few studies had addressed the role of SOX9 in CCA.19 Here, we report clinical and functional data supporting an oncogenic role and therapeutic significance of SOX9 expression in iCCA. This evidence concerns the gene SOX9 and cholangiocarcinoma.