IL6 and cholangiocarcinoma: Even more intriguingly, single-cell analysis of iCCA patient specimens showed that CCA-derived exosomal miR-9-5p elicited a high secretory possibility of IL-6 in cancer-associated fibroblasts to promote tumor progression, suggesting broader roles of cholangiocyte- derived IL-6 in the tumor microenvironment (TME) (194).