Hosted by the Chinese Academy of Military Medical Sciences, Shandong Agricultural University, Laiyang College of Agriculture and other organizations participated in the national "863" project - animal mammary gland bioreactor project made a major breakthrough, the first 28 were transferred to t-PA tissue fibrinolysis The transgenic sheep of zymogen activators were successively born in Tianyi Company, Dongying City, Shandong Province. The first born lamb was a male lamb and weighed 4.1 kg. The average daily gain of the lamb was 200 grams. The remaining 27 GM sheep were in good condition. According to reports, t-PA is currently the best thrombolytic drug for acute myocardial infarction, imported from abroad, the price is very expensive, from the animal's breast to produce t-PA drug protein, the price will be greatly reduced. As the cutting edge and frontier in today's bio-engineering, the "Animal Breast Bioreactor" project is a large-scale production of pharmaceutical proteins or other biologically active substances for the treatment and care of human diseases by preparing transgenic animals and using their mammary glands. According to experts here, research on genetically modified animals, in a sense, is to build a pharmaceutical factory on animals, that is, to pass through the animal's body and naturally process the pharmaceutical proteins that humans need. These proteins can be directly secreted into animal milk, producing large quantities. Because of its low cost and no pollution, GM research can be said to be a new way of producing biopharmaceuticals. Experts here believe that the acquisition of genetically modified sheep is only one of the important steps. The use of sheep's mammary glands as an exogenous source for the manufacture of medical proteins or drugs and its direct application to the clinic is the ultimate goal.