Support is requested for a Keystone Symposia meeting entitled Immune Evolution in Cancer, organized by Suzanne Ostrand-Rosenberg, Olivera J. Finn and Lisa M. Coussens. The meeting will be held in Whistler, British Columbia, Canada from March 9-14, 2014. Neoplastic progression is initiated by accumulations of somatic mutations in proliferating cells that cause "healthy" cells to sustain survival programs and resist embedded tissue-based programs designed to restrain their unchecked proliferation. Concurrent with neoplastic progression, the immune system sculpts the neoplastic cell repertoire by eliminating immunogenic cells while allowing outgrowth of less immunogenic variants, a process known as immunoediting. As neoplasms undergo early progression, they often resemble a chronic "wound" wherein activated tissue remodeling, and immune and angiogenic programs facilitate the survival of potentially malignant cells. Cells of the adaptive and innate immune systems are particularly important during wound healing, however during cancer development, many immune cells are co-opted and effectively "reprogrammed" towards a tumor- promoting phenotype. As a result, malignant cells condition their environment to facilitate their progression by co-opting multiple immune effector cell populations. Presentations at this conference will focus on how the tumor microenvironment perturbs lymphoid and myeloid cells, the mechanisms used by immune cells to promote tumor growth, and the strategies being developed to counteract tumor-induced immune suppression to generate anti-tumor immunity. Many of the tumor-promoting effects of the immune system are regulated by leukocyte infiltration, e.g., chronic inflammation, thus this conference, in conjunction with the companion conference on Inflammation, Infection and Cancer, will provide an in-depth examination of the current understanding of tumor progression, and will facilitate interactions between tumor immunologists and cancer biologists.