ESR1 and cancer: To rule out the possibility that the requirement of macroH2A1 in EMT in MDA-MB-231 cells has already been bypassed by certain genetic mutations in these cancer cells, we also generated stable HMLE mesenchymal cells (whose EMT induction is regulated by macroH2A1), by treating HMLE-Snail-ER and HMLE-Twist-ER cells with 4-OHT for 16 days and FACS sorted the resulting CD44Hi/CD24Lo cells.