CD4 and neoplasm: Moreover, we found higher CD8+/Treg cell ratios in tumors expressing the TTP transgene and higher levels of IFN-γ production by CD8+ tumor-infiltrating lymphocytes (TILs) derived from TTP-expressing tumors, versus PD-L1 Δ3′ UTR tumors expressing TTP (Figure 7H); however, we did not find significant differences in CD4+ TIL populations (data not shown).