NOS2 and neoplasm: M1 macrophage-derived exosomes loaded with antisense oligonucleotides (ASOs) targeting STAT6 induce the expression of nitric oxide synthase 2 (NOS2), an M1 macrophage marker that leads to the remodeling of the tumor-immunosuppressive microenvironment and the activation of CD8 t-cell-mediated adaptive immune responses (115).