FOXP3 and neoplasm: Selumetinib, MSU-42011, and the combination significantly reduced the percentage of FOXP3+CD25+CD4+ Treg (~52%; ~38%; ~56% vs. vehicle, p < 0.0001) and decreased the mean fluorescence intensity (MFI) of CD206+ (~33%, p = 0.0004; ~43%, p < 0.0001; ~45%, p < 0.0001 vs. vehicle) and CD163+ tumor-promoting macrophages (~49%; ~46%; ~62% vs. vehicle, p < 0.0001) (Figure 2E), in agreement with the reduction in FOXP3 and CD206 expressions observed by IHC analysis (Figure 2D).