Mitofusin 2 downregulation, causing decreased mitophagy or autophagy, was also observed in cardiac injury mimicked by angiotensin II (Xiong et al., 2019), in intervertebral disc degeneration (IVDD) (Chen et al., 2020) and in acute-on-chronic liver failure (ACLF) (Xue et al., 2019a,b). Here, MFN2 is linked to acute-on-chronic liver failure.