Stiffness in our tissues causes tension in our cells. Research from the Buck Institute, the University Health Network (University of Toronto), Stanford University, and the University of Alberta shows that stiffness impacts the innate immune system by upping its metabolism. The findings suggest the cellular tension likely sets off an inflammatory loop that contributes to the development of chronic diseases of aging. Publishing in Cell Reports, Buck Associate Professor Dan Winer, MD, and colleagues present an emerging way of looking at how the immune system functions, possibilities for new immunotherapeutics, and a call for scientists to reconsider the way they do research.