Natural Resistance to Tumors and Viruses : Springer : 9783642680717 : 3642680712 : 09 Jan 2012 : Natural resistance is now coming to be recognized as a potentially important phenomenon in host defense against infection and ma­ lignancy. Genetically controlled resistance mechanisms are usUally effective early in infection and before conventional immune responses are generated. Comparisons of experimental systems where natural resistance plays a prominent role demon­ strate the complexities of the host defense mechanisms involved, as evidenced in the present volume. Nevertheless, some com­ mon components of genetic resistance are discernible and largely comprise natural killer cells, macrophages, and interferon These and additional factors would seem to constitute a first line of de­ fense in host resistance against both viruses and tumors. It is evi­ dent that considerable variation in the relative importance of di­ stinct mechanisms may be found among various resistance sy­ stems and t