Figure 6.

Effect of cell density on 17β-estradiol (E₂)-induced proliferation. Different densities of MCF-7 cells enriched for membrane estrogen receptor-α (mER^high; shaded bars) and MCF-7 cells depleted for membrane estrogen receptor-α (mER^low; open bars) were treated for 5 days with 10 nmol/l E₂. The controls were treated on a separate plate with ethanol vehicle (0.1%). Values are expressed as percentage change from control. All experimental mean values (error bars are ± standard error) were significantly different (P < 0.002) from the control (first bar on the left).