12 December 1979 
Donald S. Frederickson, M.D. 
Director, National Institutes of Health 
Bethesda, Maryland 20205 
Dear Dr. Frederickson: 
I note that the proposed recombinant DNA Guide Line Revisions 
have now been published in the Federal Register and that now is the 
period for public comments. I wish to inform you of my opinion 
that these revisions will substantially facilitate research using 
recombinant DNA techniques. Because of the power of this method- 
ology, the major advances in molecular genetics which have occurred 
rapidly during the last several years should come at even a faster 
rate since we now know that these experiments are safe and therefore 
can be done without the physical and biological containment restric- 
tions previously applied. 
Sincerely yours. 
cWief, Clinical Hematology Branch 
[ 454 ] 
