Lonnie Lybarger, PhD, is an Associate Professor in the Department of Cellular and Molecular Medicine within the College of Medicine at the University of Arizona. Dr. Lybarger’s research program focuses on the mechanisms that regulate the activation of immune responses. In particular, his group studies a process known as antigen presentation, which is central to many aspects of the immune response against pathogens and tumors. This work includes detailed analyses of the cell biology of antigen presentation, as well as the study of its impact on immune responses. Recently, Dr. Lybarger has begun to study the critical link between antigen presentation and the regulation of metabolic homeostasis, with relevance to conditions such as type II diabetes.Research in the Lybarger lab has been funded by grants from State and National agencies. He has been an author/co-author on ≈35 original research reports, with his major contributions coming in the field of antigen presentation. Many of these reports involve collaborations within the University of Arizona and with colleagues at other institutions. Dr. Lybarger has served as a reviewer for University and National granting agencies, as well as reviewing for many research journals. In addition, Dr. Lybarger has served as a primary research advisor to a number of graduate and undergraduate students, while contributing to the classroom instruction of medical and graduate students.