IL4 and asthma: Airway inflammation during asthma attacks also seems to be regulated by the molecular clock: in mice lacking BMAL1 in myeloid cells, induced attacks of allergic asthma were reported to be more severe than in wild-type controls and characterized by higher concentrations of chemokines (IL-4, IL-5) and eosinophils in the lung and serum; indeed, these results may explain the increase in asthma attacks at night, when the expression of BMAL1 is reduced [58].