Dr. Kenneth Weinberg's laboratory's efforts are aimed at understanding the reciprocal interactions between immature T lymphocytes (“thymocytes”) and thymic epithelial cells, the stromal cells of the thymus which support T lymphocyte development. Such interactions are abnormal in both genetic diseases of children like severe combined immune deficiency (SCID) and the DiGeorge syndrome, and in aging and autoimmune diseases. The Weinberg laboratory uses novel in vivo human and murine models to understand the mechanism of such interactions and to identify stem and progenitor cell populations which can be used as therapy for a range of immune diseases.