TGFB1 and cholangiocarcinoma: LIF secretion may be induced by several pro-inflammatory cytokines, such as TNF-α, IL-6, IL-1β and TGF-β, variably released by macrophages and activated T-cells populating the local inflammatory microenvironment [12, 13, 25], as well as by the hypoxic conditions typically featured in CCA [17].