MKI67 and neoplasm: Tumor cell proliferation, as measured by Ki67, was also significantly decreased in the I+ICB group compared to U+IgG- treated mice (p < 0.05), as was tumor cell proliferation in the U+ICB and I+IgG groups (Figure 6C, p < 0.01), in agreement with tumor growth control observed by these treatment groups compared to U+IgG treatment in Figure 5C. Analysis of immune subsets revealed a significant upregulation of PD-L1-expressing CD8+ and NK cells following ICB treatment (U+ICB) compared to IgG control-treated mice (U+IgG) (Figure 6D, p < 0.001 and p < 0.05, respectively).