Intracellular signalling plays an essential role in immune system development and function. We are interested in how the intracellular signalling molecules communicate with each other and co-ordinately determine T and B lymphocyte development and function. Using the powerful conditional gene targeting technology, my laboratory has generated various mouse models and used these models to dissect the regulatory mechanisms by which various intracellular signalling networks control the development and function of hematopoietic stem/progenitor cells, lymphocytes, dendritic cells (DCs) under physiological and pathological conditions.