Fig. 1

Oncostatin M (OSM) is highly expressed in ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). a To detect the presence of OSM in breast cancer tissue, histological microarrays from 72 patients with breast cancer were stained with human OSM antibody by IHC. Twelve patients had in situ DCIS, 54 patients had nonmetastatic IDC, and 16 patients had IDC with metastasis to lymph nodes (see Additional file 1). The results showed that normal adjacent tissue expresses little OSM but that OSM is highly expressed in DCIS and IDC. Secondary antibody alone did not produce any background signals. b Intensity quantification of OSM stained tissues. Mean staining intensity for DCIS (2.00) and IDC (1.66) tissues was significantly higher than that of normal adjacent tissue (1.33) and metastatic tissue (1.24). There was no statistically significant difference between normal and metastatic tissue. Multiple cores from the same patients were averaged. Data are expressed as mean ± SD. *p < 0.05 by one-way analysis of variance with Tukey’s multiple comparisons test