Zhijian ‘James’ Chen is an Investigator of Howard Hughes Medical Institute, and George L. MacGregor Distinguished Chair in Biomedical Science and Professor in the Department of Molecular Biology at the University of Texas Southwestern Medical Center at Dallas. Chen discovered the regulatory role of ubiquitination in protein kinase activation in the NF-B and MAP kinase pathways. In addition, he discovered the Mitochondrial Antiviral Signaling (MAVS) protein that reveals a new role of mitochondria in immunity. More recently, Chen discovered cyclic GMP-AMP synthase (cGAS) as a cytosolic DNA sensor and a new cyclic di-nucleotide signaling pathway that mediate innate immune responses in animal cells. For his work, Chen has received numerous honors including the National Academy of Science Award in Molecular Biology (2012) and the American Society of Biochemistry and Molecular Biology (ASBMB) Merck Award (2015). He was elected to the National Academy of Sciences in 2014.