Georg Holländer is Hoffmann and Action Medical Research Professor of Developmental Medicine at the University of Oxford. He is distinguished for his seminal studies in thymic biology. He pioneered research in thymic epithelial cell development and function in relation to the acquisition of an immune system tolerant of the host. He has redrawn the previously established lineage differentiation map for thymic epithelium, which has since influenced efforts to therapeutically regenerate this compartment in vitro and in vivo. His work has made fundamental contributions to the pathogenesis of autoimmunity and graft-versus-host disease, provides the rationale for novel diagnostic tools and builds the foundation for innovative treatments of congenital and acquired thymus disorders in man.