Antinuclear Antibodies

knowledge of gene regulation, particularly in neoplastic cells, this deficit is striking. With our current understanding of chromosomal translocations, point mutations, and gene amplification in tumor cells, it is surprising to read that there is ". . . no difference between cancer and normal DNA . . ." (p. 130). The author spends a fair amount of time discussing possible mechanisms for the carcinogenicity of phorbol esters without discussing the currently held belief of the importance of protein kinase C in the pathway. Other areas, such as the processing of mRNA, similarly get inadequate treatment. For all of this, the book is not without merit. Most of the omissions can be ascribed to a delay in publishing after completion of the manuscript. In consequence, one unfamiliar with the field might get a skewed impression of current knowledge. A worker in the area of gene regulation, however, who can place this book in a proper perspective can find much to gain. The basic premise of the author is that agents which are carcinogenic and those that induce differentiation in in vitro systems, do so, either directly or indirectly, by altering the physiochemical structure of DNA. Specifically, they induce strand separation leading to subsequent DNA or RNA synthesis, respectively. Furthermore, DNA from neoplastic cells differs from normal DNA in susceptibility to some of these changes. A number of weaknesses are present in this thesis; however, the real strength of the book lies in the large number of systems cited in defending the author's case. Of particular interest was the reference to tumors in plants-an area with which most tumor biologists are unfamiliar. The induction of plant tumors by the bacterium Agrobacterium tumefaciens was of special import (tumor virologists take note!). As this volume is not encyclopedic, and at points strikingly out of date, a reader outside of the field might be misled by the presentation. Despite the book's weaknesses, a tumor biologist will still find much of merit.