Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer. One of the distinguishing features of HCC tumors is their dense network of blood vessels. This makes Angiopoetin-2, a protein that promotes vessel formation in tumors, an attractive target for fighting HCC. In a recent study, researchers discovered a novel route HCC tumors use to release Angiopoetin-2. Test-tube experiments revealed that tumor cells wrapped Angiopoetin-2 in tiny sacs called exosomes. and delivered them to cells derived from human umbilical cord, which boosted blood vessel formation. Gene editing allowed the team to knock out the gene controlling Angiopoetin-2, which, once delivered, significantly reduced the generation of new lifelines from healthy cells. The results point to a new way of disrupting tumor growth. and could lead to new therapies for cancer of the liver and other organs.