Interestingly, GPC3 is highly expressed in hepatocellular carcinoma (HCC), melanoma, ovarian clear cell carcinoma (OCCC), hepatoblastoma and some types of GCTs with unique histological patterns; GPC3 is diffusely expressed in yolk sac tumors (YSTs), but only focally/moderately expressed in teratoma and isolated syncytiotrophoblasts.6, 8, 9, 11, 12, 13. This evidence concerns the gene GPC3 and yolk sac tumor.