DOV13 cells were treated with the indicated S1P concentrations +/− 25µM Rac inhibitor (Rac-I) A- Invasion assay performed as described in methods. Rac inhibition is here seen to counteract S1P’s effects on Dov13 cell invasion. B- Gelatinase activity in CM from invasion chambers, performed as above, correlates with invasion results of 0.5µM S1P treated cells but shows negative correlation to invasion of control and 20µM S1P treated cells. Bars represent average activity of 2–3 assays relative control without S1P and inhibitors, with error bars=SEM. ***, ◆ ◆ ◆=p<0.0005; **, ◆ ◆=p<0.005; *, ◆=p<0.05. Stars (*)-S1P treatment relative to control, diamonds (◆) - Rac-I treated cells relative to respective cells without inhibitor.