CD8A and neoplasm: After presenting tumor antigens, DCs activate CD4 + T cells, resulting in IL-2 production and T-cell proliferation and development.223 Prepared CD4 + T cells produce IL-21, which induces CD8 + T cells to establish a cytotoxic phenotype and prevents them from increasing into collapsed subclones.224–227 A recent study revealed a cellular triad associated with anticancer activities.223 The intratumoral cellular triad consists of DCs, CD4 + T cells, and CD8 + T cells.