PECAM1 and neoplasm: As shown in Fig. 3, the density of α-smooth muscle actin (α-SMA) (a marker of TAFs) and CD31 (a marker for tumor vasculature) in the nanovaccine and anti-CTLA-4 mAb groups was lower than that of the PBS group, whereas the density of CD8 (a marker for CD8+ T cells) was higher than that of the PBS group.