Uric acid signals for enhanced antitumor immunity. (A) Tumor growth measurements for animals treated with dying tumor cells, either alone or along with various concentrations of uric acid (UA) prior to tumor challenge. Control animals (none) received 25 μg UA. Each data point is a mean (± SEM) tumor measurement calculated from 6 animals per group. A similar experiment yielded similar results. (B) Survival curves for mice, treated the same as in panel A, over a course of 75 days. The experiment is representative of 2 similar independent experiments. (C) Tumor growth measurements in animals treated with dying tumor cells and 25 μg UA alone or following depletion of either CD8 or CD4 T cells. Control animals received no treatments. Measurements are the mean (± SEM) of 4 animals per group. A repeat experiment gave identical results.