Extensive KPNA2 expression was observed in 3/3 dysgerminomas, 4/6 yolk sac tumors, 7/9 immature teratomas and 4/4 mixed ovarian germ cell tumors (mixed with yolk sac tumors and embryonal carcinomas), and 1/1 embryonal carcinoma. The gene discussed is KPNA2; the disease is yolk sac tumor.