Among patients from cohort B, GPC-3 levels exhibited a weak correlation with the size of the major HCC nodule (rs = 0.201, 95% CI 0.085–0.312; p = 0.001), and were significantly higher in patients with multifocal HCC than those with unifocal tumor (123, 69–226 pg/mL vs. 74, 43–149 pg/mL; p < 0.001). Here, GPC3 is linked to hepatocellular carcinoma.