THE INSTITUTE FOR CANCER RESEARCH 
7701 BUBHOLME AVENUE 
FOX CHASE • PHI LADEIPHIA, PENNSYLVANIA 10111 
(316) 343 - lOOO ■ CABLE ADDRESS: CANS E4HCH 
December 17, 1979 
Dr. Donald S. Fredrickson 
Director 
National Institutes of Health 
Bethesda, Maryland 20014 
Dear Dr. Fredrickson: 
Although at present I am not working with recombinant DNA, 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 P1/EK1. 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, 
MJB :me 
[ 514 ] 
THE FOX CHASE CANCER CENTER 
