Analysis of the pleiotropic effects of IL-33 on multiple immunological cells (macrophages, mastocytes), as well as neurological cells of medulla oblongata, dorsal root ganglion, antigen-induced arthritis system, carrageen, and formalin, shows that this alarmin plays curtail, yet not fully known role in mediating inflammation, especially in chronic inflammatory pulmonary diseases such as asthma, COPD, and OSA. Here, IL33 is linked to asthma.