PDCD1 and neoplasm: We found that the mean concentrations of the soluble lymphocyte activation gene 3 (sLAG-3), Toll-like receptor 2 (sTLR-2), programmed cell death-1 (sPD-1), and programmed death-ligand 1 (sPD-L1) receptor proteins from naïve C57BL/6 mice were comparable to the untreated tumor-bearing group on day 19 and pre-euthanasia period (Fig. 6g–h).