The cytochrome P450 proteins are monooxygenases that catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids, and other lipids.

[9] The enzyme plays a role in several pathophysiological processes including hemostasis, cardiovascular disease, and stroke.

[10] The human thromboxane A (TXA) synthase is a 60 kDa cytochrome P450 protein with 533 amino acids and a heme prosthetic group.

[11] Moreover, the study of cDNA clones made possible by polymerase chain reaction techniques has further elucidated the TXA synthase's primary structure.

[12] Mutagenesis studies that made substitutions at that position resulted in loss of catalytic activity and minimal heme binding.

The negatively charged oxygen attacks the carbonyl, and the electrons from one of the double bonds are drawn to the carbocation, thus closing the ring.

Dysregulation of TXA synthase and an imbalance in the prostacyclin-thromboxane ratio are thought to underlie many pathological conditions, such as pulmonary hypertension.

Research has led to the proposal that TXA synthase contributes to a range of tumor survival pathways, including growth, apoptosis inhibition, angiogenesis, and metastasis.