Treatment with E2 enhanced the growth of T47D cells and fulvestrant inhibited its growth. (A, B) Influence of E2 or fulvestrant on the cell cycle status of T47D cells. (A) Cells were treated with E2 for 16 hours before being analyzed by flow cytometry. (B) Cells were treated with E2 for 12 days. Fulvestrant was added to the medium 12 hours before E2 treatment. (C) The growth curve of E2 or fulvestrant treated T47D cells and control cells were plotted for 6 days of cell culture.