Figure 1: Prostanoids are generated through the COX induced metabolism of arachidonic acid. PGH2 is generated and further metabolized to PGE2, PGF2α, PGD2, PGI2 and TXA2 through specific synthases. PGE2 binds to the G-protein coupled receptors EP1, EP2, EP3 and EP4. EP receptors activate the ERK, STAT and JNK downstream signalling pathways through binding PGE2. Intracellular Ca2+ is increased through EP1 receptor activation. cAMP levels are altered through EP2, EP3 and EP4 receptor activation. ATP; adenosine triphosphate, ERK; extracellular-signalregulated kinase, JNK; c-Jun N-terminal kinase, STAT3; signal transducer and activator of transcription 3, Src; proto-oncogene tyrosine-protein kinase, PLC; phospholipase C, DAG; diacylglycerol, PIP2; phosphatidylinositol 4,5-bisphosphate, IP3; inositol trisphosphate, PKC; protein kinase C, cAMP; cyclic adenosine monophosphate, PI3K; Phosphoinositide 3-kinase, PGFS; PGF synthase, PGDS; PGD synthase, PGES; PGE synthase, PGIS; PGI synthase, TxS; thromboxane synthase.