CTL’s and NK cells with the help of dendritic and CD4+ T-cells are able to recognize and eliminate tumor cells.<unk>  are white blood cells that have left the bloodstream and migrated towards a tumor. They include T cells and B cells and are part of the larger category of ‘tumor-infiltrating immune cells’ which consist of both mononuclear and polymorphonuclear immune cells, (i.e., T cells, B cells, natural killer cells, macrophages, neutrophils, dendritic cells, mast cells, eosinophils, basophils, etc.) in variable proportions. Their abundance varies with tumor type and stage and in some cases relates to disease prognosis<unk>  can often be found in the tumor stroma and within the tumor itself. Their functions can dynamically change throughout tumor progression and in response to anticancer therapy Very high magnification micrograph of<unk> , abbreviated<unk> , in a case of colorectal carcinoma.<unk>  may also be spelled tumour<unk><unk> . H&E stain.<unk>  are implicated in killing tumor cells. The presence of<unk>  in tumors is often associated with better clinical outcomes (after surgery or immunotherapy).
Tumor-infiltrating lymphocytes
Intraepithelial lymphocyte
Tingible body macrophage
Reactive lymphocyte
Cancer-associated fibroblast
Marginal zone B-cell
Follicular dendritic cells
Circulating tumor DNA