PTGS2 and hepatocellular carcinoma: Given the above information, several previous works have suggested the potential contribution of melatonin to overcome HCC through various mechanisms including targeting the expression survivin and X-linked inhibitor of apoptosis (XIAP) via the cyclooxygenase-2 (COX-2)/phosphatidylinositol 3-kinase pathway (PI3K/Akt) pathway [160].