Particularly, type 2 (T2)-high asthma is a complex endotype associated with high type 2 inflammatory markers including immunoglobulin E (IgE), interleukins (IL)-4, IL-5, and IL-13 [8], and it is characterized by AHR, eosinophilia, and excessive airway mucus production [9,10]. Here, IL4 is linked to asthma.