Book Review Infections and Human Cancer (Cancer Surveys. Vol. 33.) Edited by R. Newton, V. Beral, and R.A. Weiss. 396 pp. Plainview, N.Y., Cold Spring Harbor Laboratory Press, 1999. $93. 0-87969-549-8 Microbes and Malignancy: Infection as a cause of human cancers Edited by Julie Parsonnet. 465 pp., illustrated. New York, Oxford University Press, 1999. $75. 0-19-510401-3