ESR1 and breast carcinoma: To address the question of the relevance of the ERα/Gα13/RhoA/ROCK/moesin signaling cascade on breast cancer cell movement, we pretreated T47-D or MDA-MB-468 (ER-) breast cancer cells with cytosine arabinoside (1-(β-D-arabino­furanosyl)­cytosine hydrochloride-Ara-C, 100μM), an inhibitor of DNA strand separation that prevents cell division (so to dissect the actions of estrogen on movement from those on cell proliferation), and we performed horizontal migration assays.