Cancer Immunology and Immunotherapy Program: Summary/Abstract The overarching scientific goal of the Cancer Immunology and Immunotherapy Program (CII) is to advance the understanding of the interplay between the immune system and cancer to discover new strategies for immune- based immunotherapies and to mitigate therapeutic resistance. Overall, CII Program research has led to advances in the understanding of the molecular basis for immune cell recognition of tumors, evasive mechanisms evolved by tumors to escape immune surveillance, how the microenvironment influences the immune response to cancer, and technological advances in genetic engineering of T cells for adoptive cell therapies. The CII Program is a new program since the prior competing renewal. The HDFCCC-wide realignment of research programs enhances opportunities for direct interaction between discovery scientists and clinical investigators within the CII Program and between programs. Research strengths of members include expertise in immunology, immunotherapy, the tumor microenvironment, cellular therapy, and immune therapeutic resistance. The CII Program provides a unique opportunity to address issues related to disparities in the catchment area in leukemia, multiple myeloma, lymphoma, melanoma, and lung cancer, with special attention placed on understanding differences in the overall clinical responses as well as access to novel immunotherapies in this diverse population. CII members are therefore positioned to translate HDFCCC discovery science into the clinic, and to bring clinical observations back to HDFCCC laboratories. Specifically, CII members conduct research to (1) define the mechanistic interplay between cancer and the immune system, (2) advance therapeutic interventions to improve outcomes with cancer immunotherapy, and (3) identify mechanisms of resistance to cancer immunotherapy.