CD8A and neoplasm: As shown in Fig. 2B, only a very small fraction of CD8+ splenocytes isolated from unimmunized control mice expressed granzyme B, while 25.6% of CD8+ splenocytes from vaccinated/tumor challenged mice expressed this CTL effector (n = 6/group; t test, p<0.05; relative to control group; Fig. 2B, D).