Fulvestrant and Breast Cancer Cells (IMAGE) Indiana University Caption The figures show that fulvestrant-mediated cytoplasmic localization of ER is associated with intermediate filament proteins CK8 and CK18. After treatment of MCF-7 and T47D cells (breast cancer cells) with fulvestrant, dramatic cytoplasmic localization of ER was observed. The results indicate that the presence of CK8 and CK18 is necessary for fulvestrant-induced cytoplasmic localization of ER, which keeps the receptor away from the nucleus where it could activate growth promoting genes. Credit Kenneth Nephew Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.