UNIVERSITY of PENNSYLVANIA PHILADELPHIA 4 NorMAN Toprinc, M.D. Vice-President in Charge of Medical Affairs October 22, 1956 Dr. Joshua Lederberg University of Wisconsin Madison, Wisconsin Dear Dr. Lederberg: I have just talked with Dr. Hilary Koprowski, and he tells me that he just received a letter from you which indicated that you might be interested in the possibilities at the Wistar Institute here in Philadelphia. The Wistar Institute is in the middle of our campus, and even though it is a separate corporation with its own endowments and Board of Managers, it is gradually being drawn closer to the University. I think it hes great possibilities as a research insti- tute, and this opinion is shared rather widely. These possibilities, however, have not been fully realized for some years, and it is our desire to bring them into reality. I wonder if it would be possible for you to come to Philadelphia on November 7th and 8th, so that you can see the Wistar and have a chance to talk with some of your friends here at the Uni- versity, particularly, Dr. David Goddard, whom I know you are acquainted with,and others. Dr. Koprowski has indicated that he will be able to be here on these days. If it will be possible for you, we will be happy to defray your expenses for this trip. Please let me know as soon as possible so thet the necessary arrangements can be made. I am looking forward to having the opportunity to discuss some of these things with you. NTemac