CXCR4 and neoplasm: Compared to the oe‐NC group, the number of CD4+ T cells and CD8+ T cells was significantly increased in the tumor tissues of mice in the oe‐NC+M2pep‐Cs NPs/Plerixafor group; while, these numbers were significantly decreased in the tumor tissues of mice in the oe‐CXCR4 group.