S100A16 expression in tissues and cell lines. (A) qRT-PCR analysis of S100A16 expression in 20 pairs of breast cancer tissue and adjacent tissue. Of these 20 pairs of tissues, 14 showed significantly higher S100A16 mRNA expression in the cancer tissue compared with the adjacent tissue (P < 0.05). (B) A scatter plot showed the mean expression level of S100A16 mRNA in breast cancer tissue was significantly higher than that in adjacent non-cancerous tissue (*P < 0.05 by paired t-test). (C) Western blot analysis of S100A16 expression in eight breast cancer cell lines and a normal breast cell line MCF10A. It was expressed in MCF10A and five breast cancer lines including MCF-7. (D) Representative examples of immunostaining (×400). In non-cancerous tissue, few S100A16 immunostaining was observed, while the expression of S100A16 was significantly higher in cancerous tissue than non-cancerous tissue, especially in the invading front of cancerous tissue.