Metabolism as a driver of immune response All living organisms need energy and metabolic building blocks to sustain biological processes. Wang et al. review immunometabolism, applying the principles of life history theory. They highlight recent advances showing the reciprocal interactions between systemic metabolism and immunity, as well as how inflammation can alter the functional state of metabolic organs and their central control by the hypothalamus. Such coordinated cross-talk between whole-body and immune cell metabolism is involved in a variety of health and disease states. Science , this issue p. eaar3932