Fig. 1

The landscape of the tumor microbe microenvironment and the tumor immune microenvironment. Microbes, microbial residues, and microbial metabolites reside within tumors, herein defined as the tumor microbe microenvironment. Intra-tumoral microbes come from the tissue where tumors initiate or from distal organs or metastasis through penetrated vessels. The major cells types in tumor immune microenvironment are divided into two categories: One is inflammatory and includes active CD8⁺ T cell, helper 1 T cell, dendritic cell, natural killer cell, natural killer T cell, M1-like macrophage, and so on; the other one is immunosuppressive and includes M2-like macrophage, regulatory T cell, helper 17 T cell, MDSC, inactive CD8⁺ T cell and so on. Abbreviations: CD = cluster of differentiation, MDSC = myeloid-derived immunosuppressive cell