SDF-1 treatment induced the tyrosine phosphorylation of FAK in CTS cells. Total cell lysates from CTS cells unstimulated or stimulated with SDF-1α for the indicated times were immunoprecipitated with anti-FAK antibody. The immune complexes were subjected to immunoblotting analysis with anti-PY antibody (4G10) (upper panel) and anti-FAK antibody (lower panel). The increase in tyrosine phosphorylation of FAK is indicated (by fold increase) based on the densitometry values.