Advances in the molecular understanding of carcinogenesis and immunology have transformed the development of targeted anticancer drugs addressing both the tumor and the immune system. The efficacy of these therapies depends on the target associated signal transduction and/or interaction of different types of cells. Previous unpublished data (Figure 1) suggested potential subclassification of breast cancer cases based on activity of (Her-2 associated) signal transduction pathways. However, these data were obtained from single-plex immunohistochemistry (IHC) performed on serial sections. Recent findings in tumor immunology as well as advantages in technology enabling multiplex immunofluorescence staining and evaluation using digital image analysis were all taken into consideration to refine previous analysis.
