For example; Zhang et al., 2019 [186] demonstrated the role of PD-1 blockade in increasing anti-tumor activity of specific DCs called DC-stimulated cytokine-induced killer cells (DC-CIK) generated in presence of anti-CD3 antibody, IFNγ, poly-hydroxyalkanoates and IL-2; characterized by co-expression of CD56 and CD3 or CD3 and CD8 markers. This evidence concerns the gene PDCD1 and neoplasm.