As type 2 inflammation (which is associated with higher disease severity and recurrence) seems to be the predominant endotype in 85% of CRSwNP in the Western world, biologics targeting IL-4, IL-5 and IL-13 in severe asthma became novel treatment options for CRSwNP, especially in the case of co-morbid asthma and N-ERD (10, 11). This evidence concerns the gene IL4 and asthma.