EDNRB and breast cancer: In contrast to the results with breast cancer cell lines, we observed a trend of higher EDNRB-532 and lower EDNRB-442 in grade III compared to grade I breast cancer samples (Fig. 1G), suggesting involvement of stromal cells in EDNRB isoform expression and implicating EDNRB-532 as an isoform associated with advanced disease.