As mentioned above, MDSCs and TAMs are key components of the tumor‐associated microenvironment that promotes tumor progression and metastasis.[qv: 31,32] MDSCs rather than other myeloid cells, such as neutrophils and monocytes/macrophages, significantly increased in Brca1 mutant MG (Figure 7A), but not in Brca1 mutant tumor (Figure S9D, Supporting Information). This evidence concerns the gene BRCA1 and neoplasm.