Robert D. Schreiber is the Alumni Endowed Professor of Pathology and Immunology, Professor of Molecular Microbiology, Co-leader of the Tumor Immunology Program of the Siteman Comprehensive Cancer Center at Washington University and Founding Director of the newly formed Washington University Center for Human Immunology and Immunotherapy Programs. Schreiber’s career has focused on elucidating the biochemistry and molecular cell biology of cytokines and defining their role in immune responses to cancer. He was among the first to demonstrate that interferon-gamma (IFNg) was the cytokine that activated macrophage anti-tumor and anti-microbial activities and pioneered the in vivo use of monoclonal antibodies to define the physiologic roles of cytokines in promoting host responses to tumors and infectious agents. He elucidated the structure and function of the IFNg receptor and established the physiologic relevance of IFNg receptor-dependent signaling by generating genetically engineered mice lacking specific components of this pathway. Using IFNg-unresponsive- and immunodeficient gene-targeted mice, Schreiber then demonstrated that the immune system could eliminate spontaneous and carcinogen-induced primary tumors or maintain cancer in a dormant state thereby unequivocally demonstrating that immunity can prevent cancer development. However, he also demonstrated that immunity sculpts the immunogenicity of cancer cells rendering them more fit to survive in an immunocompetent environment. Based on these findings, Schreiber proposed the term “cancer immunoediting” to emphasize the host-protective and cancer-promoting capacities of immunity, a concept that has gained nearly universal acceptance in the last few years. Schreiber’s work has led to a generalized appreciation of the profound effect of immunity on developing tumors and has contributed critical conceptual and practical support to the fields of tumor immunology and cancer immunotherapy. Recently, Schreiber used genomics approaches to identify the targets of cancer immunoediting as tumor-specific mutant proteins that function as tumor-specific neoantigens. He subsequently adapted this approach to demonstrate that tumor-specific neoantigens are the favored targets of T cells undergoing reactivation following checkpoint blockade cancer immunotherapy and are highly effective as a basis for personalized cancer immunotherapy. Robert Schreiber has authored more than 300 peer reviewed and invited publications and has received many honors including the 2014 AACR Lloyd J Old Prize in Cancer Immunology. He was inducted into the American Academy of Arts and Sciences in 2010 and the National Academy of Sciences (USA) in 2013.