EP4 on tumor cells promote tumor cell migration, invasiveness, EMT, stem cell activity, angiogenesis (by upregulating VEGF-A), and lymphangiogenesis (by upregulating VEGF-C/D); EP4 on lymphatic endothelial cells promote lymphangiogenesis by upregulating VEGF-C/VEGFR3. This evidence concerns the gene PTGER4 and neoplasm.