Prostaglandin E synthase encoded by PTGES is a glutathione-dependent prostaglandin E synthase. The expression of PTGES has been shown to be induced by proinflammatory cytokine interleukin 1 beta (IL1B). Its expression can also be induced by tumor suppressor protein TP53, and may be involved in TP53 induced apoptosis. Knockout studies in mice suggest that PTGES may contribute to the pathogenesis of collagen-induced arthritis and mediate acute pain during inflammatory responses.