IL4 and asthma: Type 2 inflammation occurs in approximately 70% of severe asthma patients and is promoted by a broad network of hyper-expressed cytokines, namely IL-4, IL-5, and IL-13, and several immune cells, including mastocytes, type-2 helper lymphocytes, type-2 innate lymphoid cells, basophils, and eosinophils [4,5].