Sal-Like Protein 4 (SALL4), is a zinc finger transcription factor found in germ cells and human blood progenitor cells, with functional involvement in modulating Oct-4 to maintain embryonic stem cell pluripotency. SALL4 is a useful marker for acute myeloid leukemia, B-cell acute lymphocytic leukemia, intratubular germ cell neoplasia, seminomas/dysgerminomas, and yolk sac tumors (both pediatric and postpubertal). Anti-SALL4 is used to detect embryonal carcinomas, hepatocellular carcinoma (HCC), gliomas, ovarian primitive germ-cell tumors, choriocarcinomas, spermatogonia, teratoma, gastric cancer, breast cancer, and lung cancer. Expression of SALL4 is often associated with poor prognosis in HCC, and with metastasis in endometrial cancer, colorectal carcinoma, and esophageal squamous cell carcinoma.