The high safety profile and the capacity to reduce circulating eosinophils made Mepolizumab the best option for patients with type-2 CRSwNP, severe asthma, unfit for surgery, and concomitant heavy levels of hematic eosinophils (> 1500 cell/μL), both at baseline or arose after anti-IL-4/IL-13 administration [34, 35]. This evidence concerns the gene IL4 and asthma.