Notably, research using a dual-tumor immunocompetent mouse model revealed that the systemic suppression of antitumor immunity is mediated by the coordinated activation of Treg cells and MDSCs.369 Unbiased scRNA-seq has also revealed that hepatic monocyte-derived CD11b + F4/80+ macrophages play a critical role in inducing antigen-specific CD8 + T-cell apoptosis via the Fas‒FasL pathway, thereby reducing peripheral T-cell numbers and further impairing antitumor immunity370 (Fig. 6c). This evidence concerns the gene CD8A and neoplasm.