ESR1 and breast cancer: However, in contrast to most (Lymperatou et al., 2013; Park et al., 2016), but not all studies (Sisci et al., 2010; Gao et al., 2017; Padilla-Rodriguez et al., 2018), we show that 10−9M E2 inhibits ER+ breast cancer cell migration, which may be attributed to differences in methodology like different cell lines, induction periods, culture conditions and the use of mytomycin C, an inhibitor of cell proliferation used to accurately identify the migratory potential.