Program Name Change: The Symbiosis, Infection and Immunity (SII) Program is replacing the Symbiosis, Defense and Self-Recognition Program. The name change was made to more accurately reflect the research that the program supports. Proposals focused on research into the processes and mechanisms mediating antagonistic or beneficial interactions within and between viruses, prokaryotes, and eukaryotes (with the exception of plants) will be reviewed in this program. These interactions can include cross- and within-kingdom interactions and may scale from the level of cells to organisms. The program encourages studies of immunity (scaling from molecules to cells to systems), mechanisms responsible for self/non-self-recognition, and microbial manipulation of immune defenses. Research in these areas focused on plants should be submitted to the Plant Biotic Interactions program. For a full description of the program, and contact information, please visit the SII Program page.