A single thymic epithelial cell (red) in contact with developing T cells (white). Researchers at the universities of Basel and Oxford have for the first time identified all genes regulated by the protein Foxn1. The results show that Foxn1 not only plays a crucial role in development of the thymus in the embryo, but it also regulates vital functions in the developed, postnatal organ. The decryption of the protein's functions is important in the understanding and treatment of autoimmune diseases, vaccination responses in old age and defense against tumor cells. The study was published in the journal Nature Immunology.