Shc immunoprecipitation on lysates from 32D/WT and 32D/Y764F cells. Serum- and growth factor-deprived cells were stimulated for 5 or 15 minutes at 37°C with G-CSF or IL-3. The blots were hybridized with antiphosphotyrosine antibodies and reprobed with anti-Shc antibodies to confirm equal loading of Shc.