Dose response for E2, tamoxifen, and ICI 182,780. (A) PCY2 yeast. (B) RS188N yeast. The figure is representative of three to four independent experiments. The points shown are means ± SEM. The curves areas follows: E2 (●), ICI 182,780 (▴), and tamoxifen (■). Point C is the response in the absence of added E2.