Absolute number of agar colony types stimulated with EGF.

Colony composition stimulated with (A) 20 ng/mL and (B) 0.7 ng/mL EGF by each receptor construct is shown. Differentially shaded bars represent the number of each colony type. Numbers of G (*), GM (**), or M (***) colonies stimulated by the receptor mutant are significantly different from those stimulated by the WT receptor. Data are presented as the mean ± SE of 3 independent experiments.