IL1RL1 and asthma: 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.