Tph-1 is essential for the generation of protective T cell–mediated antitumor immunity. (A) MB49 was inoculated, and tumor growth was monitored over time in all the groups. One group received 5-HTP every other day from the day before the start of experiment. Data show mean ± SEM of n = 6–8 mice/group and are representative of results from three independent experiments. P-values listed are for the group they are shown next to in comparison with WT female mice and were determined by two-way ANOVA. (B) On day 11 after tumor inoculation, whole tumor draining LNs were isolated, plated, and restimulated with irradiated tumor to determine IFN-γ ELISPOTS after 18 h and IL-17A ELISPOTS after 36 h, restimulated for 18 and 36 h, respectively. Data show mean ± SEM for n = 10–16 mice/group and were pooled from three independent experiments. The p-value shown was determined for the indicated groups by Tukey posttest after one-way ANOVA analysis. (C) MB49 was inoculated systemically through the tail vein in age-matched female WT and Tph-1^−/− mice as well as female W^sh mice systemically reconstituted with BMMCs from WT and Tph-1^−/− mice. The graph is compiled from three independent experiments with total numbers of mice indicated in the figure. The p-value was determined by log-rank comparison between the two BMMC-reconstituted groups.