Researchers led by George Church, whose findings helped spur the U.S. human genome project in the 1980s, have copied the part of a living cell that makes proteins, the building blocks of life. The finding overcomes a major roadblock in making synthetic self-replicating organisms, Church said today in a lecture at Harvard in Cambridge, Massachusetts. The technology can be used to program cells to make virtually any protein, even some that don’t exist in nature, the scientists said. That may allow production of helpful new drugs, chemicals and organisms, including living bacteria. It also opens the door to ethical concerns about creation of processes that may be uncontrollable by life’s natural defenses.