On the other hand, when LMM3 tumor cells were inoculated in naïve mice, tumor-bearing mice produced a weak (if any) anti-tumor immune response (Suppl. Figure 3), which was correlated to a) high expression of PD-L1 on the surface of tumor-infiltrating CD11b+ myeloid cells (Fig. 2F) and b) increased expression of PD-1 in the surface of both T CD8+ and CD4+ splenic lymphocytes (Suppl. Figure 4). This evidence concerns the gene CD4 and neoplasm.