UNIVERSITY OF CALIFORNIA SAN FRANCISCO MEDICAL CENTER BERKELEY * DAVIS + IRVINE * LOS ANGELES * RIVERSIDE * SAN DIEGO * SAN FRANCISCO SANTA BARBARA * SANTA CRUZ A Tribute ta the Peopte of California SCHOOL OF MEDICINE SAN FRANCISCO, CALIFORNIA 94122 LABORATORY OF RADIOBIOLOGY August 14, 1968 Professor J. Lederberg Department of Genetics Stanford University School of Medicine Palo Alto California 94304 Dear Professor Lederberg: 3S I enclose a reprint of my paper on the skin disease Xeroderma pigmentosum which was published in Nature, May 18, 1968. Iam sorry for the delay, but we did not receive the reprints until this week. All of us in this laboratory were extremely pleased that you took note of this piece of our work, and saw fit to use it as an example in your Washington Post article. We appreciated the sentiments you expressed in the Washington Post very much. There is no doubt, whatsoever, that we could never have done this work on Xeroderma pigmentosum without the prior work on microorganisms which provided us with the techniques and the framework of thought. We are now extending our work to other skin diseases and to heterozygous individuals in the hope of finding other genetic defects associated with DNA repair. # A4AYATD Thank you, again, for your interest and for the encouragement that such interest has given us. ° Yours/sincerel af finer © lau bf’ . Cleaver, Ph. Dv \ssistant Professor of Radiobiology JEC:sp Ene.