Osteopontin could also be detected in the stroma, while tumor cells staining positive for this protein appear to be present on the edges of the tumor (Additional file 1: Fig. S5G); however, there was no difference in osteopontin expression between tumors in the luminal B or the low-ER TMAs (Additional file 1: Fig. S5H). The gene discussed is SPP1; the disease is neoplasm.