Biomarkers that have been extensively studied in CRS, such as eosinophil count, IgE, and IL-5, have been associated with a TH2 inflammatory endotype which correlates with an eosinophilic CRSwNP phenotype that predicts a poorer prognosis, tends to recur after conventional surgical treatment, but responds to glucocorticoid treatment. The gene discussed is IL5; the disease is chronic rhinosinusitis with nasal polyps.