AFP and hepatocellular carcinoma: Although their utility is somewhat limited due to differences across ethnic populations and underlying etiologies of HCC, studies have suggested that when used in combination with each other, as well as with AFP, they can show an excellent diagnostic performance (i.e., area under the curve (AUC) > 90%) particularly when enriched within exosomes (rather than when detected in exosome-depleted serum fractions) [141,142,143,144].