We observed that the T cell checkpoint receptor, PD-1, was upregulated in more than 70% of the tumor-associated CD8 T cells (Fig. 4a), and PD-1 ligand (PD-L1) was expressed on the majority of tumor-associated myeloid cells following ISF35 therapy (Fig. 4b), suggesting that PD-1 engagement could limit antitumor activity. This evidence concerns the gene CD8A and neoplasm.