TBXA2R and asthma: A good example of these is 8-epi-prostaglandin F2 alpha (8-epi-PGF2 alpha), which has also been shown to cause contraction of smooth muscle by triggering the thromboxane A2 receptor (TBXA2R) [25, 27], and has been shown to have a role in asthma and EIA [28, 29].