TRPA1 and idiopathic pulmonary fibrosis: Transient Receptor Potential Ankyrin 1 (TRPA-1) is another receptor subtype which is usually co-expressed with TRPV-1 and also responds to noxious stimuli and cold temperatures [15].The evidence for its role in pathological cough is unclear, however given the co-localisation of the two channels and anecdotal evidence that patients with IPF find their cough worse in cold conditions, it is possible that co-operation occurs.