A protein that evolved long before the human circulatory system may help unlock stronger cancer treatments. When C3 is produced inside tumors, it blocks immune-suppressing cells and gives immunotherapy a better chance to work. Researchers were even able to recreate this effect in resistant tumors, significantly improving survival in mice.
An immune molecule that appeared in evolution long before blood circulation may help improve cancer immunotherapy. Scientists at Nagoya University in Japan discovered that complement C3 can prevent immune-suppressing cells from building up inside tumors, but only when the protein is produced locally within the tumor. C3 traveling through the bloodstream did not influence how well treatment worked.
The findings, published in Nature Communications, suggest that reproducing this local effect could benefit patients whose tumors do not produce enough C3 naturally.
https://www.sciencedaily.com/releases/2026/08/260806050702.htm
