Overexpression of the c-erbB-2 oncoprotein in human breast carcinomas: immunohistological assessment correlates with gene amplification.

Amplification of the human protooncogene c-erbB-2 was found in 12 of 36 human breast tumours and was associated with increased levels of expression of the c-erbB-2 protein, measured both by immunohistological staining and by western blotting. The use of immunohistological staining to detect the level of expression of the c-erbB-2 protein in human breast adenocarcinomas may be of value in predicting tumour behaviour.