IL4 and asthma: Whether modern steroid-sparing anti-inflammatory treatments are disease modifiers remain controversy as the therapeutic effect of allergen immunotherapy is modest and therapeutic effects of biologics targeting IgE, IL-5, IL-4, IL-13 are maintained in in adults with established asthma.40, 41, 42 Although biologic agents can be effective add-on therapies for patients with type 2–high severe asthma, no biologic drugs are currently available for type 2-low severe asthma.43