Our research group is interested in the structural characterization of protein complex involving cell-cell communications such as cell-cell interactions and receptor-ligand interactions, and their subsequent signaling pathways. These structural information of protein complex can unveil their underlying molecular mechanism such as how proteins interact with each other, how they undergo conformational changes upon by their interactions, and how they perform subsequent signalings. For this, we use not only the traditional molecular biology/biochemistry but also two biophysical cutting edge techniques – X-ray crystallography and Single particle EM. We facilitate protein expression and purification in a wide range of systems, including bacteria, insect cells and mammalian cells. In parallel, based on the structure of disease-related protein complex, we design new therapeutic hybrid proteins and further develop them as potential biologics.