Prior studies reported that various factors such as mucus cystatin 2, pappalysin-A, periostin levels, Charcot-Leyden Crystal mRNA levels in nasal brushing or nasal secretions, high eosinophilic infiltration and high IL-5 expression, decreasing number of mast cells, occupational dust exposure and non-IgE-mediated asthma and blood eosinophil count combined with an asthma history were predictors of relapse of CRSwNP [23,24,25,26,27,28,29,30]. This evidence concerns the gene IL5 and asthma.