Dr. Heiner Westphal presents his research on transgenic mice in this part of the Biotechnology Seminar Series. Initially, Dr. Westphal explains how outside genes are introduced into a mouse embryo creating a germ-line that is expressed in every cell of the body. He uses drawings to illustrate how the cells are implanted in the embryo. The purpose of the transplantation is to develop a model whereby a tumor can be developed in a particular part of the body. In the mouse model the cancer is developed in the lens. Dr. Westphal shows how the cancer develops day by day. Mouse models are also used to track the AIDS virus. Both CAT and TAT constructs are used. Dr. Westphal and his team found that megaloviruses can activitate AIDS in people. Further, Dr. Westphal describes how the development of a protein, human TPA, introduced in a mouse's milk can be used as an effective tumor treatment. In the future, he sees the opportunity to use embryonic stem cells as a therapy. The therapy is called homologous gene targeting. Dr. Westphal then took questions from the audience.