PTGER4 and breast cancer: Combined with our earlier reported data that COX-2 and certain EP receptors (EP1 and EP4) are responsible for promotion of cellular migration (Timoshenko et al, 2003) as well as VEGF-C upregulation in human breast cancer (Timoshenko et al, 2006), present results reinforce the place of COX-2 inhibitors and specific EP antagonists in breast cancer chemo-intervention.