As assessed by both cytokine and cytotoxicity measurements, both two kinds of XA-1 treatment were effective in PD-1 pathway inhibition with comparable EC50 values of IFN-γ stimulation in Figure 4d (EC50 = 0.06 nM for mRNA source, EC50 = 0.08 nM for CHO source) and tumor cell line killing in Figure 4e (EC50 = 0.038 nM for mRNA source, EC50 = 0.022 nM for CHO source). Here, PDCD1 is linked to neoplasm.