While a small study including eight twins (E-MTAB-2347) did not reveal TGF-β2 deregulation in primary biliary cirrhosis (PBC), Shakel et al. [54] reported on upregulation of TGF-β2 in PBC, thus providing a further link between TGF-β2 and biliary-derived liver diseases. This evidence concerns the gene TGFB2 and primary biliary cholangitis.