SALL4 and yolk sac tumor: Expression of SALL4 has been reported in various cancers such as precursor B-cell lymphoblastic lymphoma (40, 41), acute myeloid leukemia (42), myelodysplastic syndromes (43), breast cancer (44), chronic myeloid leukemia (45), lung cancer (46, 47), endometrial cancer (48), liver cancer (49, 50) gastrointestinal carcinoma (51–53), glioma (54), germ cell tumor, and yolk sac tumor (55, 56).