ESR1 and breast cancer: Pre-incubation of T47-D (Fig 7A) or MCF-7 (Fig 7B) breast cancer cells with the specific Rho-kinase inhibitor, Y-27632 (Y-27632, 10 μM) prevented the activation of moesin by estradiol, implying that ROCK-2 is required for estrogen signaling to moesin in ER+ breast cancer cells.