The Interleukin 7 cytokine receptor, encoded by the Il7r gene is expressed in various cell types of the immune system and allows these cells to be signaled by the survival factor IL7. Mutations in the IL7R signaling pathway result in primary immunodeficiency diseases such as severe combined immunodeficiency (SCID) and Omenn Syndrome and emphasize the importance of these signals in health. Polimorphisms in the gene that encodes the IL7 receptor are associated with diseases like multiple sclerosis (MS) and T-leukemias (T-ALL). The mechanism of transcription of this immunologically relevant gene has not been studied in detail and presents a gap in our knowledge of the immune system. In this basic science project, we will study the mechanism of transcription of the IL7R gene in B and T lymphocytes and in NK cells. We aim to identify the transcription factors that bind to the enhancers and promoter of the IL7R gene. In doing this, we will identify the rules that govern the control of this important cytokine receptor which gives survival signals to lymphocytes. In the current project we will generate genome edited cell lines and transgenic mice using cutting edge CRISPR/Cas9 genome engineering techniques. We will use these mice to conduct experiments on the expression of the IL7R in T, B and NK cells of the immune system.