PDCD1 and neoplasm: The tumor‐specific DC/tumor‐fusion cell (FC)/mRNA vaccine in combination anti‐PD‐1/PD‐L1/CTLA‐4 Nbs (PD‐1 Nb20, 99mTc‐Nbs C3, Nb36) could improve the activation, proliferation, cytokine secretion, and tumor cell cytotoxicity of CD8+ T‐cells [304, 305, 306].