PTGES and cancer: Recent studies have shown that ω-3 PUFAs have an inhibitory effect on the occurrence and progression of malignant tumors, while ω-6 PUFAs have a promoting effect; their mechanism of action may be related to the regulation of cyclooxygenase and prostaglandin synthetase (PGES), the main enzymes in the function and reaction of prostaglandin E3, and prostaglandin E2, and metabolites of ω-3 PUFAs and ω-6 PUFAs (17, 18).