In accordance with recent reports on the negative impact of PD-1+ myeloid cells on T-cell amplification responses (31, 32), PD-1 positivity was also evaluated, showing a similar five-fold increase for PD-1 and PD-L1 within the tumor-infiltrated CD11b+ fraction upon LLC-Fluc progression (Figure 2B). This evidence concerns the gene CD274 and neoplasm.