In contrast, IHC (Figure S5A, Supporting Information), RT‐qPCR (Figure S5B,D, Supporting Information), and flow cytometry (Figure 6K–N; and Figure S5F,G, Supporting Information) showed that the Fgfr2‐S252W;Brca1‐MKO tumors displayed unbalanced M1:M2 macrophage ratios compared with the Fgfr2‐S252W and Brca1‐MKO mammary tumors. This evidence concerns the gene BRCA1 and breast cancer.