Expression of PD-1 and its ligands likely limits the induction of tumor-specific immune responses, as high PD-L1 expression on DCs suppresses CD4+ and CD8+ T cell proliferation and promotes Treg proliferation in various diseases, including cancer.8, 96, 97, 98, 99, 100, 101 This suggests that combining DC therapy with CIs can result in a two-sided synergy by targeting not only tumor cells and immunosuppressive cells in the TME but also DCs administered during DC therapy and even T cells induced by DC therapy (Figure 1A). Here, PDCD1 is linked to neoplasm.