[Tissue-specific mammary gland antigen identified by monoclonal antibodies].

A new antigen of mammary tumor cells has been revealed using monoclonal antibodies. A similar antigen was detected also in certain types of secretory epithelia of oesophagus, stomach, salivary gland, and embryonic large intestine. Upon malignization, antigen persists in invasive ductal cancer of mammary gland and is expressed in cancers of ovary and rectum. The molecular weight of the antigen is greater than 2,000 kD.