Together, these results indicate that the depletion of Gr-1hi and Gr-1int cells, or the depletion of Gr-1hi cells alone, during the d.c. HDM sensitization, reduces the subsequent lung inflammation, suggesting that these IL-1β-expressing cells, particularly neutrophils, are crucial for d.c. HDM sensitization-triggered allergic asthma. This evidence concerns the gene IL1B and allergic asthma.