C3 Protein Inside Tumors Could Boost Cancer Immunotherapy | Science News

Science News Today | 2 Min News | The Daily News Now! · Aug 8, 2026 · 1m

Scientists have uncovered a powerful twist in cancer immunotherapy: an ancient immune molecule called C3, produced right inside tumors, acts as a gatekeeper that blocks immune-suppressing cells—letting the body’s defenses actually attack cancer. Surprisingly, C3 in the bloodstream doesn’t help; mice without tumor-made C3 saw treatment fail, while those with it thrived—even when blood C3 was removed. In lung cancer patients, higher local C3 meant better outcomes. Now researchers are racing to deliver C3 directly into resistant tumors, potentially unlocking new hope for patients who don’t…