Science researchers at Harvard University have discovered a gene found in the most devastating forms of cancer that controls embryonic stem cell self-renewal. The gene, SALL4, enables stem cells to keep dividing rather than grow into mature cells. The gene is re-expressed in almost all cases of acute myeloid leukemia and between 10 to 30 percent of lung, ovarian, gastric, liver, breast and endometrial cancer. Researchers say they can make a strong case that the gene plays a part in tumor formation. The breakthrough marks the beginning of a search for a drug that can block the gene’s activity.