ESR1 and breast cancer: Le Romancer et al. (2008) reported the hypermethylation of ERα in the cytoplasm of a subset of BCs through Arg260 methylation within the ERα DNA-binding domain by protein arginine methyltransferase 1 (PRMT1), an event that mediates the extranuclear function of ERα by triggering its interaction with PI3K and Src, involving the recruitment of a Src substrate, the focal adhesion kinase (FAK), which sustains BC cell migration [85].