TRPA1 and Airway obstruction: (Babaei et al., 2020) On the other hand, bradykinin induces cough by activation of bradykinin 2 (BK2) receptor (Al‐Shamlan & El‐Hashim, 2019), resulting in stimulation of COX and 12‐lipoxygenase (12‐LOX) metabolites release; which activate transient receptor potential (TRP) channel subfamily vanilloid member 1 (TRPV1) and subfamily A member 1 (TRPA1) channels result in an increase in both cough response and airway obstruction.