MCEMP1 and chronic asthma: Further investigation of lung mast cell phenotypes from Mcemp1–/– mice in chronic asthma model is required to examine whether Mcemp1–/– mice have defects in the development of distinct mast cell subtype clusters, induction of specific gene sets or pathways that contribute to asthma exacerbation in comparison with Mcemp1+/+ mice upon OVA challenge.