PD 153035 inhibits EGF receptor activation in 3T3-L1 cells. Cells were serum starved for 3 h and preincubated with different concentrations of PD 153035 (ab141839) for 2 h. The cells were then stimulated with 200 ng/ml EGF for 10 minutes. Cell proteins were resolved by SDS-PAGE and probed with anti-phospho-EGFr (upper panel) and with anti-phospho ERK1/2 (lower panel).