ESR1 and breast cancer: To explore the molecular mechanisms underlying the modulation of ERα and ERβ protein turnover by the Cyclopia extracts in MCF7 and T47D BC cells, translation was inhibited using a protein synthesis inhibitor, cycloheximide (CHX) (Baliga et al., 1969; Perry et al., 1995), while degradation of the ER via the UPS was inhibited using a proteasome inhibitor, MG132 (Khissiin and Leclercq, 1999; Fan et al., 2004).