There are four human SALL proteins (SALL1, 2, 3, and 4) with structural homology and playing diverse roles in embryonic development, kidney function, and cancer. SALL4 is a transcription factor. Its expression is low to undetectable in most adult tissues with the exception of germ cells and human blood progenitor cells. However, it is reactivated and misregulated in various cancers, such as acute myeloid leukemia, B-cell acute lymphocytic leukemia, germ cell tumors, gastric cancer, breast cancer, hepatocellular carcinoma, lung cancer, and glioma. Often, SALL4 expression is correlated with worse survival and poor prognosis such as in HCC, or with metastasis such as in endometrial cancer, colorectal carcinoma, and esophageal squamous cell carcinoma.