Stephen J. Weiss

Stephen Weiss's research efforts have long focused on the mechanisms used by white blood cells, endothelial cells and cancer cells to remodel tissue structure during events ranging from inflammatory disease and angiogenesis to cancer. His highly cited works on the role of metalloproteinases in regulating these pathologic events have appeared consistently in top-ranked journals such as Science, Nature, Genes & Development, the Journal of Cell Biology, the Journal of Experimental Medicine, the Proceedings of the National Academy of Sciences, Developmental Cell and Cell. Most recently, Dr. Weiss’ characterization of a family of membrane-anchored enzymes, the MT-MMPs, lends credence to his novel hypothesis that these proteases act as master switches in controlling key functions of normal and neoplastic cell behavior in vivo.

When Weiss first embarked onto his current path of research, i.e., studying the mechanisms of a group of proteinases - he calls their "molecular scissors" - his lab had been working on oxygen radicals, highly reactive small molecules "that nobody would think would ever be purposely generated in a biological system." One of the downstream products of oxygen radicals is hypochlorous acid, which both kills microorganisms and activates a latent collagenase secreted by white blood cells that can cleave their way through connective tissues, an action that he likens to removing the scissors' sheath so they can begin to cut.

Tumor cells and blood vessel cells also make molecular scissors—the human genome codes for more than five hundred varieties. Though these scissors are activated by mechanisms distinct from those used by white blood cells, Weiss is currently working on several interrelated projects exploring how cells mobilize these scissors "and use them to slice their way through surrounding tissues in order to invade and metastasize as well as build new blood vessels." A long term goal of the lab is to identify those scissors that might be turned "off" in order to offer therapeutic benefits for diseases such as cancer and other diseases where connective tissues are remodeled, such as rheumatoid arthritis.

Weiss completed his B.A. and M.D. and medical internship at Ohio State University and Washington University, then was recruited to the Division of Hematology/Oncology at the University of Michigan. In 1982, he was promoted to the rank of Assistant Professor in the Department of Internal Medicine, Division of Hematology/Oncology and in 1988, assumed the rank of Professor. In 1991, he was named as the first recipient of the Upjohn Professorship, a title that he has held for the last 20 years. Most recently, Dr. Weiss served as Division Chief of Molecular Medicine & Genetics in the Department of Internal Medicine and the Director of the Molecular Mechanisms of Disease Program at the University of Michigan before joining the Life Sciences Institute as a Research Professor in 2006. He was appointed as the Associate Director for Basic Science Research, a program encompassing more than 150 scientists, at the U-M Comprehensive Cancer Center in 2016. 



  • BA, Biological Sciences and Biochemistry, Ohio State University, 1973
  • MD, Ohio State University College of Medicine, 1977


  • American Society for Clinical Investigation  - 1984
  • Association of American Physicians
  • Institute of Medicine of the National Academy of Sciences - 2001
  • National Institute of Health committee member
  • National Cancer Institute committee member

Editorial Boards

  • Editor-in-Chief, Journal of Clinical Investigation - 1997