New work from the ӳý’s Klarman Cell Observatory, Brigham and Women’s Hospital, Harvard University, MIT, and Yale University expands the understanding of how one type of immune cell – known as a T helper 17 or Th17 cell – develops, and how its growth influences the development of immune responses. By figuring out how these cells are “wired,” the researchers make a surprising connection between autoimmunity and salt consumption, highlighting the interplay of genetics and environmental factors in disease susceptibility.