ACE2 and intrahepatic cholangiocarcinoma: In addition, a newly discovered axis, the angiotensin-converting enzyme 2/angiotensin-(1–7)/mitochondrial assembly receptor [ACE2/Ang-(1–7)/MasR] axis, has been identified, and it acts as a negative regulator of Ang II activity (Donoghue et al., 2000; Santos et al., 2008), whereas AngII induces tumor progression in intrahepatic cholangiocarcinoma (Fyhrquist and Saijonmaa, 2008; Okamoto et al., 2010).