One previous study  (64) has reported that mRNA expression of NTRK2 is elevated in bronchial biopsies of adult asthmatics and disruption of BDNF/NTRK2 signaling by NTRK2 receptor blockade down-regulates cholinergic innervation density in the airways of an ovalbumin-induced murine model of asthma, thereby ameliorating airway hyperresponsiveness. This evidence concerns the gene BDNF and airway hyperresponsiveness.