why this must be so, and Ihc relative risJc posed by either tlic 
host or the donor alone. A discussion ol the principal fallacies 
of assumption (1) follows: 
(a) One might well ask just what is meant by "harmful. " 
The question was raised by commentators during and after the 
open meeting in February, 1976 , of the Advisory Conrnittee to the 
Director of NIH, at which time the working version of the Guide- 
lines v;as made available to the public. A list of questions, 
based on public comment, was presented to the recombinant DNA 
Advisory Committee meeting on April 1-2, in which the Guidelines 
were given final revision. This list included consideration of 
the definition of "containing harm.ful genes." The Committee, 
however, spent much more time worrying about the definition of 
"contain" rather than "harmful" and the latter term remains in 
the Guidelines v;ithout a sufficiently broad definition. 
It is clear that "harmful" cannot be restricted to the effect 
a gene may have on human health solely within the context of its 
original orgaiiism. The Guidelines mention specifically the obvious 
cases of genes coding for a toxin or a drug resistance factor, 
or perhaps even allow that some may be involved in the cause of 
viral ly induced cancer. 
However, if expressed out of its normal context, one may 
argue that any gene has the potential for being "harmful." For 
example : 
(1) If a gene, carried by a viral vector, coding for a 
normal metabolic enzyme, were to enter and be expressed in 
Appendix K — 59 
