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Dr. Donald S. Fredrickson 
October 17, 1977 
to causa tumors In experimental animals. However, they transform cells 
(Including human cells) to malignancy in vitro and have been associated 
with human neoplasias by a variety of Indirect tests. 
I hope these comments are of some value to you. 
Sincerely, 
Fred Sapp, Ph.D. 
Professor and Chairman 
FR/nlc 
[Appendix A — 16] 
