TGFB1 and cholangiocarcinoma: TGF-β is markedly upregulated on liver injury, and is a tumor promoter at later stages of liver cancer, offering an understanding of probable common etiology of CCA and HCC or cHCC-CCA [21], over and above the stemness of hepatic cell development [22], with reports of greater tumor aggressiveness of the cHCC-CCA types [23].