Weill Cornell Medicine Nov 17 2025 A new study has discovered a molecular signal that tumors exploit to exhaust the T cells meant to destroy them-and how silencing that signal could revive the body's immunity. The study led by Weill Cornell Medicine researchers was published Nov. 17 in Nature Immunology and shows that tumors not only evade the immune system but can actively reprogram immune cells to stop fighting. "Our dream is to make immune-based therapies available to every patient. To