IL5 and asthma: There are currently five classes of biologics approved for treating severe asthma, including anti-immunoglobulin E (anti-IgE) (omalizumab), anti-interleukin (IL)-5 (mepolizumab, reslizumab), anti-IL5R (benralizumab), anti-IL4/IL13R (dupilumab), and anti-thymic stromal lymphopoietin (TSLP) (tezepelumab) [3–5].