THE INSTITUTE FOR CANCER RESEARCH 
ZrOl BUBHOIMI AVENUE 
FOX CHASE • PHILADELPHIA, PENNSYLVANIA 10111 
(215) 342-lOOO'CABLE ADDRESS- CAN S EA R C H 
December 17, 1979 
Dr. Donald S. Fredrickson 
Director 
National Institutes of Health 
Bethesda, Maryland 20014 
Dear Dr. Fredrickson: 
I am writing this letter to let you know that I fully support 
your position that all recombinant DNA research performed with 
E. coli strain K12 should be classified Pl/EKl. I feel that the 
potential risks of such research have been carefully evaluated by 
well-informed specialists and that this classification is a proper 
one. 
Yours very truly 
Associate JMemoer 
cam 
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THE FOX CHASE CANCER CENTER 
