We found that the mRNA levels of S100a8/S100a9 were increased in MTMG tissues at multiple developmental stages and tumor tissues (Supplementary Fig. 4a–c), S100a9 expression was increased dramatically in luminal and stromal subpopulations (Fig. 4a and Supplementary Fig. 4d), and Brca1-MT mammary epithelial cell line (G600) (Fig. 3a). This evidence concerns the gene S100A9 and neoplasm.