PDCD1 and neoplasm: Granzyme B production within the tumor microenvironment of the AA+anti-PD1 group (0.4 ± 0.06%) was significantly higher than AA alone (0.18 ± 0.07%, t test, P = 0.02), anti-PD1 alone (0.18 ± 0.03%, t test, P = 0.004), and vehicle (0.09 ± 0.015%, t test, P < 0.001) (Fig. 4B; also see SI Appendix, Fig. S5).