It is predominantly expressed in a subset of sensory neurons located in the dorsal root and trigeminal ganglia where it is primarily co-expressed with TRPV1 (<3% express TRPA1 only) as well as calcitonin gene related peptide and substance P. Physiological studies have since indicated that TRPA1 channels play an important role in in the development of thermal and/or mechanical hyperalgesia in certain inflammatory and nerve injury pain models [1,21–23]. This evidence concerns the gene TAC1 and injury.