Three isoforms of COX have been identified: COX-1, which is ubiquitously expressed in most tissues mediating prostaglandin synthesis and homeostasis in normal physiological processes; inducible COX-2, which is undetectable in normal tissues but is upregulated during both inflammation and cancer; and COX-3, which remains to be elucidated but is normally expressed in the brain and spinal cord (3, 7, 8). This evidence concerns the gene PTGS2 and cancer.