TNF and intrahepatic cholangiocarcinoma: The inflammatory cytokines, TNF-α and IL-4, can down-regulate the expression of c-Kit, and cause a reduction in the number of Kit-positive ICCs that is unrelated to apoptosis and is probably a trans-differentiation of the ICC to a type of α-smooth muscle action (α-SMA) positive cell with a smooth muscle cell phenotype [17].