The main interests of our lab focus on structural and functional studies of immune-related proteins in animal and plant innate immune systems and plant receptor-like kinases. The innate immune system is the first line of defense against invading microorganisms. NOD-like receptors (NLRs) are a large family of receptors involved in monitoring the cytoplasmic environment inside cells and initiating immune response to eliminate pathogens. Plant receptor kinases (RKs) are membrane-localized receptors that play vital roles in various biological processes including growth, development and defense. We use X-ray crystallography, cryo-EM, and biochemical techniques to study the autoinhibiton, ligand recognition and activation mechanisms of NLRs in immune defense; to elucidate ligand recognition and activation mechanisms of RKs; to discover new ligand-receptor pairs.