Rabbit Anti-Human Cox-1 polyclonal antibody for IHC-P. Cyclooxygenases 1 and 2 (COX-1, COX-2) are enzymes involved in the conversion of arichidonate to prostaglandins. COX-1 and COX-2 are very similar in structure and function, though they vary in expression. COX-1 is normally expressed in most cell types, whereas COX-2 expression is at low levels unless induced by hormonal stimuli. In some breast cancer and bladder carcinoma studies, COX-1 is expressed in the stroma cells adjacent to the tumors but not in tumor cells.