(A) SCF-induced tyrosine phosphorylation of c-kit. TC32 (PNET) and M-07e (control) cells were incubated for 10 minutes with 0.5 μg/10⁶ cells rhSCF, lysed, and immunoprecipitated with c-kit antiserum. Proteins were resolved by 7% SDS-PAGE, transferred to PDVF, and immunoblotted with antiphosphotyrosine antibody. Molecular mass of protein standards are indicated in kD. (TC32 − SCF), TC32 untreated cells; (TC32 + SCF), TC32 SCF treated cells; (M-07e − SCF), M-07e untreated cells; (M-07e + SCF), M-07e treated cells. (B) c-kit Immunoblot. The immunoblot from (A) was stripped and reprobed with an anti–c-kit MoAb.