STANFORD UNIVERSITY MEDICAL CENTER 
STANFORD, CALIFORNIA 94305 
Department of Pathology 
David Korn, M.D., Professor and Chairman 
Stanford University School of Medicine, L235 
(415) 497-5252 
December 13, 1979 
Dr. Don Fredrickson 
Director 
National Institutes of Health 
Bethesda, MD 20205 
Dear Dr. Fredrickson: 
I am in strong support for the K12/P1 recommendation to change the 
requirements for DNA cloning in E. coli K12 organisms. The current guide- 
lines are, I believe, now proven to be unnecessarily stringent. In 
addition, the bureaucratic requirements to process superfluous MUA’s 
has created a logjam which has already seriously impaired the timely progress 
of important projects. Even my own projects have been significantly delayed 
by that process . 
Yours sincerely. 
Irving Weissman, M.D. 
Associate Professor of Pathology 
ILW: jac 
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