PTGER4 and neoplasm: Regulation of PGE2 receptor subtypes, such as EP4 gene expression, has been shown to be involved in the influencing activation of several kinases including ERK in other studies demonstrating the complicated signalling networks that affected the tumour growth and progression, and the indispensable role of EP4 prostanoid receptor as a therapeutic target for the cancer treatment 50, 51, 52.