In contrast to COX-1 which is constitutively expressed in nearly all tissues and mediates the synthesis of prostaglandins required for tissue homeostasis, COX-2 expression is inducible and increases in response to various stimuli including inflammatory signals, mitogens, cytokines, and growth factors, as would occur in the presence of infection, inflammation, and neoplastic processes [61]. This evidence concerns the gene PTGS2 and infection.