Although choriocarcinoma of the ovary is histologically identical to primary gestational choriocarcinomas, previous studies have not yet investigated the expression of GPC3 in GTN (including gestational choriocarcinoma, PSTT and ETT) or other trophoblastic lesions, such as exaggerated placental site (EPS) and PSN. Here, GPC3 is linked to gestational trophoblastic neoplasm.