Regarding the M1-like polarization of tumor-infiltrating macrophages, representative results of the flow cytometric analysis of tumor-infiltrating CD80+ F4/80+ and CD86+ F4/80+ macrophages are shown in Figure 5F. The percentages of both tumor-infiltrating CD80+ F4/80+ and CD86+ F4/80+ macrophages were higher in mice treated with the PEK protein vaccine plus anti-PD-L1 Ab than among those treated with the PEK protein vaccine plus PBS (18.37 ± 0.10% vs. 13.14 ± 0.10% and 13.61 ± 0.19% vs. 9.97 ± 0.16%, respectively, p < 0.001 for both, Student’s t-test; Figure 5G). Here, CD274 is linked to neoplasm.