Transient receptor potential cation channel, subfamily A, member 1, also known as transient receptor potential ankyrin 1 or TRPA1, is a protein that in humans is encoded by the TRPA1 (and in mice and rats by the Trpa1) gene. TRPA1 is an ion channel located on the plasma membrane of many human and animal cells. This ion channel is best known as a sensor for pain, cold and itch in humans and other mammals, as well as a sensor for environmental irritants giving rise to other protective responses (tears, airway resistance, and cough).