CD8A and neoplasm: Immune cell analysis of spleen and tumor tissues showed that short Bifidobacterium strains alone enhanced antitumor immunity by the increasing cluster of differentiation (CD)8+ T-cell and effector CD8+ T-cell numbers and by increasing CD8+ regulatory T cells (Treg) and effector CD8+/Treg ratios (Table 1) (Yoon, et al., 2021).