The different levels of cooperation between monocytes/macrophages and CD8+ T cells in regressing tumors after immunotherapy. In progressing tumors, tumor-educated macrophages contribute to inhibiting CD8+ T cell activities (a). Upon immunotherapy, macrophages release inflammatory cytokines and chemokines (b), concomitant with macrophage pyroptosis. It attracts and guides new myeloid cells and CD8+ T cells to infiltrate the inflamed tumor. Monocytes/macrophages can also kill tumor cells (c), following activation by IFN-γ-producing CD8+ T cells (d), and some subsets might locally reactivate the CD8+ T cells through antigen cross-presentation (e), increasing the probability of tumor cell killing. As the tumor regresses, a natural negative feedback loop (f), that goes along with the activation of effector cells, progressively terminates the immune response. Created with BioRender.com (https://biorender.com/ accessed on 10 June 2022).