MRGPRX2 and allergic asthma: Given our previous demonstration that MRGPRX2-expressing MCs are increased in lung MCs of asthmatics (24) and the finding in the present study that MrgprB2-mediated β-arr2 biased signaling contributes to AAI suggests that specific MRGPRX2 antagonists could be utilized for the treatment of allergic asthma in humans.