To dissect the roles of tumor-derived PGE2 and EP4 receptors on the LEC in the lymphangiogenic events, we measured the effects of C3L5- CM, exogenous PGE2 and EP4 agonists on LEC proliferation, migration and tubulogenesis, showing a stimulation of all the three events with all of the above agents. Here, PTGER4 is linked to neoplasm.