CD4 and neoplasm: The nanoparticle-based delivery of the STING activator has also increased the antitumor immune response (increased M2 to M1 macrophage polarization, IFN-γ producing T cells, tumor cell apoptosis, and CD4+ and CD8+T cell infiltration in the tumor microenvironment) in the PD-L1-insensitive triple-negative breast cancer (160).