A, Scatchard analysis of [125I]EGF binding to CaSki cells and the effects of epinephrine and 17β-estradiol. B, Modulation of EGF-induced DNA synthesis by AG1478, PD98059, and wortmannin. Data are means ± SD of three independent experiments. *, P < 0.01 [EGF category, for both AG1478 vs. C (control) and PD98059 vs. C].