CD8A and neoplasm: Immunization with tEV plus SyBV led to a significant increase in lymphocyte infiltration compared to the other groups (Figure 5a), and especially CD8+ T cells (Figure 5b) and natural killer (NK) cells (Figure 5c) in tumour tissue were highly infiltrated in mice immunized with tEV plus SyBV, and this correlated with the inhibition of tumour growth in this group (Figure 4d).