Contraction of airway smooth muscle in human and guinea pig tissues was observed in vitro with TRPV4 agonists, and this condition may exacerbate asthma.405 McAlexander et al. suggested that activation of TRPV4 leads to airway constriction in humans and is entirely dependent on the production of cysteine leukotrienes.406 Therefore, activation of TRPV4 may exacerbate symptoms in patients with asthma. This evidence concerns the gene TRPV4 and asthma.