IL4 and Allergy: Finally, the microbiome profiles were correlated with patient characteristics (i.e., age, sex, medical treatment, smoking behavior, and disease severity), CRS phenotype features (i.e., nasal polyps, allergies, and asthma), and the concentrations of inflammatory markers (i.e., interleukin-5 [IL-5], IL-13, IL-4, and interferon gamma [IFN-γ]) measured in the serum of the CRS patients.