ARG1 and hepatocellular carcinoma: By querying the GEPIA and Kaplan-Meier Plotter database (Tang et al., 2017; Menyhárt et al., 2018), we found HCC patients with high expression of CPS1, OTC, and ARG1 had higher overall survival rate (Figures 4E,F and Supplementary Figures 2D,E, 3D,E), which might be due to the low expression of CPS1 in patients with advanced HCC.