By inserting DNA for the human antithrombin protein into single cell embryos of goats, scientists have been able to genetically engineer goats that produce high levels of antithrombin in their milk. The purified protein is used to create a drug called ATryn, an anti-clotting(血液凝固を妨げる)drug intended to help people with hereditary antithrombin deficiency. People who suffer from the rare disorder are especially vulnerable to life-threatening blood clots. Until now, antithrombin has been produced from blood products collected from human donors, but this new source could provide a more steady supply.