CD8A and neoplasm: The remaining cells were nine immune cell populations comprising the tumor immune microenvironment, including B cells (B), CD4 + T cells (CD4), CD8 + T cells (CD8), dendritic cells (DC), granulocytes (Gran), mast cells (Mast), macrophages (Mφ), natural killer cells (NK), and regular T cells (Tregs) (Fig. 1f).