Expression of S100A9 in gastric cancer and adjacent non-cancerous tissues. (A) Different expression value of S100A9 in 72 gastric cancer tissues and paired no-cancerous tissues by analyzing data from illumina Sentrix BeadChip cDNA microarray. (B-E) Immunohistochemical staining of S100A9 in gastric cancer tissues (B) metastatic lymph nodes (C), chronic gastritis (D), and adjacent non-cancerous gastric mucosa (E). S100A9 localization was revealed as brown or red granulated loci in the cytoplasm of infiltrating inflammatory cells, especially in mononuclear phagocytes and neutrophil granulocytes. (magnification 200×).