Moreover, immunohistochemical examination demonstrated that the tumor cells were positive for glypican-3 (GPC3) (Figure 5), AFP (Figure 6), hepatocyte paraffin-1 (Hep Par 1), cytokeratin (CK)18, and hepatocyte antigen, but negative for CK7, CK20, placental alkaline phosphatase (PLAP), prostate-specific antigen (PSA), cancer antigen 125 (CA125), epithelial membrane antigen (EMA), cluster of differentiation (CD) 117, and CEA, which confirmed that the seminal vesicle tumor was metastatic HCC. This evidence concerns the gene GPC3 and hepatocellular carcinoma.