In an independent external validation cohort (n = 102; Table S7), where fewer metabolites were tested, a signature comprising five out of our 10 available metabolite candidates (aspartic acid, glutamic acid, taurine, serine, and AA) plus AFP, achieved an AUC of 87%, with a sensitivity of 79% and a specificity of 82% to discriminate HCC and controls (Fig. 5B and Fig. S10). This evidence concerns the gene AFP and hepatocellular carcinoma.