Researchers at the Harvard Stem Cell Institute (HSCI) are pursuing a gene called SALL4 as a potential new target for cancer treatment. SALL4 encodes a transcription factor, a type of protein that modifies when and how much other genes get expressed. Until now, cancer therapies have not focused on transcription factors; instead, most cancer drugs act on kinases—proteins that modify other proteins. SALL4 is normally only expressed in embryos. However, it can become active again in adults and promote tumor formation. Active SALL4 is found in almost all cases of acute myeloid leukemia (AML), a type of blood cancer, as well as in many patients with other types of cancer, including lung cancer. In two studies, HSCI researchers found that blocking either the SALL4 gene itself or its protein product suppressed cancer cells and improved survival in mouse models of AML and liver cancer. The scientists are now hoping to develop cancer treatments that target SALL4.