Stimulation with granulocyte colony-stimulating factor (G-CSF) induces myeloid precursor cells to di erentiate into neutrophils, and tyrosine phosphorylation of certain cellular proteins is crucial to this process. However, the signaling pathways for neutrophil di erentiation are still obscure. As the Src-like tyrosine kinase, Lyn, has been reported to play a role in G-CSF-induced proliferation in avian lymphoid cells, we examined its involvement in G-CSF-induced signal transduction in mammalian cells
