Co-expression of transcription factor AP-2beta (TFAP2B) and GATA3 in human mammary epithelial cells with intense, apicobasal immunoreactivity for CK8/18.

AP-2β is a new mammary epithelial differentiation marker and its expression is preferentially retained and enhanced in lobular carcinoma in situ and invasive lobular breast cancer. In normal breast epithelium AP-2β is expressed in a scattered subpopulation of luminal cells. So far, these cells have not been further characterized.

Transcription factor AP-2beta in development, differentiation and tumorigenesis.

To date, the AP-2 family of transcription factors comprises five members. Transcription factor AP-2beta (TFAP2B)/AP-2β was first described in 1995. Several studies indicate a critical role of AP-2β in the development of tissues and organs of ectodermal, neuroectodermal and also mesodermal origin.