STUB1 and hepatocellular carcinoma: Using the UbiBrowser database (version 1.0) (Li et al., 2017), we predicted several potential E3 ligases, including SYVN1, NEDDL4, and STUB1 (Figure 5A), but only SYVN1 was found to significantly inhibit GLUD1 protein levels in HCC cells (Figure 5B).