Figure 2: IL‑15/IL‑15Rα EP DC can activate both NK cells (A) and CTL (B) in order to eliminate tumor cells. The interaction between IL‑15/IL‑15Rα- complexes and IL‑15Rβγ-expressing cells can further activate the latter (a). Interaction between the immune checkpoint receptor PD‑1 and its ligand PD‑L1 has an inhibitory effect on the activation of CTLs and NK cells (b). Abbreviations: CTL: Cytotoxic T Lymphocytes; IL-15: Interleukin-15; IL‑15Rα: Interleukin-15 Receptor Alpha; NK: Natural Killer Cell; PD-1: Programmed Cell Death Protein 1 Receptor; PD‑L1: Programmed Death‑Ligand 1; TC: Tumor Cell.