A: Mono-Mac 1, THP-1 and U937 cells were treated for 24 hours with medium alone or cFMS-I and were re-stimulated with and without colony-stimulating factor 1 (CSF-1) for 20 minutes. Phospho-extracellular-signal regulated kinase (ERK) and total ERK are shown. B: Mono-Mac 1 cells were treated with medium alone, cFMS-I, sunitinib, or U0126 for 24 hours and were re-stimulated with and without CSF-1 for 20 minutes. Phospho-ERK and total ERK are shown. C: Western blot of CSF-1R expression in Mono-Mac 1, THP-1, and U937 cells. D: The expression of CSF-1R in Mono-Mac 1 with and without 5 minutes of CSF-1 treatment cells. E: Mono-Mac 1 cells were pre-treated with cFMS-I or sunitinib for 24 hours and were then treated with CSF-1 for 5 minutes. Immunoprecipitation for CSF-1R followed by western blot or phospho-tyrosine and CSF-1R and F: for total cFMS.