Elevated c-Src activity in invasive lobular breast cancer (LBC) cells. (a) atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS) surrounded by invasive carcinoma cells. In situ lesions are marked with asterisks. Arrows point to examples of invasive cells with strong c-Src activity. (b) Nonneoplastic epithelium (membranous E-cadherin) surrounded by invasive carcinoma cells with active c-Src. (c) Nonneoplastic (E-cadherin) and neoplastic in situ components (dotted line) surrounded by and interspersed by invasive cells. (d) Immunohistochemical examples of an invasive lobular carcinoma (ILC) with moderately increased c-Src activity (left, LCIS marked with asterisk), an ILC with strong c-Src activity (middle), and a LCIS with low c-Src activity (right). To assess the extent of immunohistochemical c-Src staining, H-scores were determined to be 155 for ILC and 53 for LCIS (left), 291 for ILC (middle), and 51 for LCIS (right). An antibody against total c-Src was used as control.