Extensive SALL4 expression was observed in 3/3 dysgerminomas, 6/6 yolk sac tumors, 6/9 immature teratomas and 4/4 mixed ovarian germ cell tumors (mixed with yolk sac tumors and embryonal carcinomas), 1/1 embryonal carcinoma, compared with the normal ovarian specimens. This evidence concerns the gene SALL4 and yolk sac tumor.