In addition, immunohistochemical staining of C57BL/6 tumor tissues suggested that the quantity of CD8+ T cells in the MC38-ENTPD2 group was significantly lower than that in the MC38-Vector group (P < 0.05, Fig. 3B); thus, it is rational to hypothesize that ENTPD2 can affect the CD8+ T-cell response. Here, CD8A is linked to neoplasm.