PDCD1 and neoplasm: In the KPC-3403 tumor, though a-PD-1 increased the percentage of granulocytes and G-MDSCs in KPC-3403 tumors, the addition of mTGF-β-TRAP in the combination group decreased the percentage of G-MDSCs compared with the a-PD-1 monotherapy group (Figure 3, C and D).