It has a number of distinct clinical phenotypes caused by interactions of different leukocytes, epithelial cells, and stromal cells, and while asthma is classically thought of as a type 2 immune response disease mediated by cytokines IL-4, IL-5, and IL-13, other T cell types such as Th1, Th17, Treg, and NKT cells are implicated in asthma pathology [107,157,158,159,160,161]. Here, IL4 is linked to asthma.