Summary The immune system is the foundation to maintain health. Enhanced ability to manipulate the immune system will enable us to precisely unleash the power of the immune system to combat against virtually all diseases. For example, cancer is one of the major health challenges in the US and around the world. Recently, major breakthroughs have been made by manipulating immune cells to fight cancer. However, these methods are currently imperfect, often encounter irresponsiveness to primary treatments, acquired resistance, or systemic toxicity due to failure to control the cytotoxic cell activity that damage host organs, or inflammation induced cytokine storms. Moreover, the immune system has enormous diversity and plasticity, which can go beyond control under pathological settings in an immunological disorder, or under artificial settings of immunotherapy. Many immunotherapy targets remain to be discovered in an unbiased manner. Identification and characterization of key immunomodulatory genes and pathways in vivo remains a critical bottleneck in the expansion of the immunotherapeutic armamentarium. My goal is to innovate new platforms to precisely engineer the genome and transcriptome of immune cells in a high-throughput manner, and apply them to identify and characterize new genes fundamental for T cell function and anti- tumor activity. To approach this goal my lab has recently developed a high-throughput screening system in CD8+ T cells, and successful performed T cell genetic screens in vivo, which identified multiple genes modulating the phenotypes of CD8+ T including cells trafficking, survival, tumor infiltration, and effector function. In the first program of this project, we will interrogate newly discovered immunotherapy targets including surface proteins, signaling or regulatory proteins, and metabolic enzymes, which will yield new insights on how they regulate T cell's function and anti-tumor activity. We will develop new agents and methods for pharmacological inhibition of the validated and clinically relevant targets as new routes of treatments and test them in pre-clinical settings. In the second program, we will further innovate next- generation immunogenetics tools. We will generate a genetic toolbox for better control of T cell gene expression, and couple it to high-throughput screening system for identification of new sets of immunotherapy targets that acts mainly through gene expression. Finally, we will engineer T cell signal transduction circuitry for more efficient activation of T cell function. These studies, if successful, will lead to new platforms for high-throughput in vivo immunogenetics, new targets to modulate T cell function and anti- tumor activity, as well as provisional concepts of first-in-class agents for immunotherapy.