PDCD1 and neoplasm: While the anti-GITR:mIgG2a group showed the expected drop in the CD4+ CD25+ Helios+ population in the tumor to below 5%, the anti-TIGIT:mIgG2a group did not show any signs of intratumoral Treg depletion, instead displaying around 25% of CD4+ T cells in the tumor being CD25+ Helios+ (Figure 4) which is similar to the anti-PD-1 group.