To confirm our findings from the scRNA‐seq resource, we next performed immunofluorescence staining of B16‐F10 mouse tumor specimens and we observed that Fulvestrant combined with anti‐PDL1 increased the infiltration of CD8+, CD4+, and GZMB cells into the tumors compared to the control group (Figure 4D,E). This evidence concerns the gene CD4 and neoplasm.