Mast cell-expressed membrane protein 1 (MCEMP1) is a type II transmembrane protein predominantly expressed in myeloid lineage immune cells, including lung-resident mast cells and alveolar macrophages. MCEMP1 is a critical factor in allergic and inflammatory lung diseases, with higher expression levels correlating with increased disease severity. However, the molecular mechanisms underlying the role of MCEMP1 in the pathogenesis of lung inflammatory diseases remain unclear.