Lastly, while GPC3 exhibits high specificity for HCC, rare cases of positivity have been reported in non-HCC tumors, such as melanoma, nonseminomatous germ cell tumors (e.g., yolk sac tumor, and choriocarcinoma), gastric adenocarcinoma, rare cases of cholangiocarcinoma, neuroblastoma, and lung squamous cell carcinoma [58,59]. This evidence concerns the gene GPC3 and cholangiocarcinoma.