PTGER4 and neoplasm: We have shown that PGE2-EP4 signaling plays a specific and important role in driving pro-tumor myeloid cell differentiation and function, and that pharmacological blockade of EP4 signaling by E7046, a novel EP4 antagonist in early clinical development, is able to largely reverse PGE2-induced myeloid immunosuppression and thus promote anti-tumor immune responses.