Alexander Rudensky wants to understand the molecular mechanisms governing the differentiation and function of CD4 T lymphocytes and their role in immunity and tolerance. Rudensky and his team are working to understand the roles that regulatory T cells play in control of autoimmunity, tumor immunity, and immunity to infections, as well as the establishment and maintenance of immune homeostasis at environmental interfaces. They are particularly interested in the plasticity of regulatory T cell transcriptional and functional programs and the molecular mechanisms of regulatory T cell lineage stability.