Of the serum proteins associated with neutrophilic asthma status, five (MMP 9, EDAR, PLA2G2E, IL1RL1, and Elafin) were complementary to established clinical factors and related to airway remodelling pathways in asthma cases (MMP-9), neutrophil recruitment, with one possible anti-inflammatory protein, Elafin. This evidence concerns the gene MMP9 and asthma.