Research in our laboratory focuses on molecular mechanism of lymphocyte development and genetic basis of lymphoid diseases such as leukemia and autoimmune disorders. We are using mouse models to investigate the role of E2A and other related transcription factors in lymphocyte development and immune function. We have shown that E2A plays an essential role in regulating both B and T cell development. Mice deficient for E2A cannot produce any B cell and exhibit high incidence of T cell leukemia. Separate studies also indicated that E2A is involved in the development of autoimmune disorders. Our current and future studies are to combine genetic, molecular biology, and immunology means to determine gene expression programs during lymphocyte development.