The theme of the 2013 Gordon Research Conference on Chemical and Biological Terrorism Defense is "Multi-disciplinary Approaches to Chemical and Biological Defense". This conference will highlight the highly multi-disciplinary, cutting-edge research in the field of chemical and biological defense; talks will focus on chemical agents and bioterrorism-related pathogens that impact humans, plants, and/or animals. Major topic areas will include: chemical defense research with an emphasis on early host response to chemical agents and the use of cutting edge biological approaches to develop preventative countermeasures; host pathogen interactions and basic virulence mechanisms; cutting edge research on biodetection of pathogenic microorganisms and early diagnosis; immune suppression and evasion strategies of pathogens; agents of agricultural bioterrorism with an emphasis on basic mechanisms of virulence and parallels to mammalian host-pathogen interactions. The 2013 Conference will be preceded by the Gordon Research Seminar (GRS) on Chemical and Biological Terrorism Defense. The GRS is planned by and for pre-doctoral and post-doctoral trainees in the field of chemical and biological defense on topics related to those listed above. This unique forum provides an opportunity for our future leaders in the field to present their research as lectures and posters in a collegial and interactive environment. Goals for the 2013 Conference are to focus on cutting edge basic research, encourage participation of junior scientists and graduate students, and integrate multi-disciplinary approaches relevant to both chemical and biological threats. The Conference will provide a forum for interaction between scientists from a variety of disciplines and afford an opportunity for a robust interdisciplinary discussion of the topics presented and the challenges that lie ahead.