April 7, 1960

Dr. Falconer Smith

Radiation Biology Sect.on
National Cancer Institute
National Institutes of Health
Bethesde 14, Maryland

Dear Dr. Smith:

Thank you for your letter of March 28th. { think thot | would
in general agree with the interpretation you discussed for your
experiments on antibody formation in mice with plasma cell tumors,
There must be some homeostatic mechanism governing the total amount
of globulin produced and liberated into the serum. The preponderance
of the myeloma type globulin in these mice already speaks for a
competition between the formation of normal globulin, Including C,
antibodies, and the unique globulin produced by the plasma cell “S
tumor. This competition may very well be e celluler competition.
{ think it would be quite useful to inquire what proportion of the
total "normal globulin’! in your secondarily a@munized animals

Bs)
corresponds to the new antibody. Insofar as this globulin is .
repressed in the tumor bearing animals, a very large proportion ;
of it should prove to be the new antibody. a aa

Yours sincerely,

Joshua Lederberg
Prefessor of Genetics