A. The naïve (lane 1–4) and dif-HC15 (lane 5–8) cells were stimulated with 100 pM IL-5 for 0 min (lane 1, 5), 5 min (lane 2, 6), 15 min (lane 3, 7) or 10 ng/ml PMA for 10 min (lane 4, 8). Band intensities of pERK1/2 were normalized to that of Grb2, and then normalized to that of lane 1. Data are summarized as the mean ± (SEM) from three independent experiments. NS=Not Significant. * p<0.05, N=3. B. Naïve and dif-HC15 cells were treated with 10 nM CCL5, 100 nM fMLP or 100 nM CCL11 for 0 or 2 min. Cell extracts were then prepared and immunoblotted as detailed under Materials and Methods. Representative immunoblots of pERK1/2 and Grb2 from three independent experiments are shown.