IL6 and allergic asthma: To characterize the effect of TCZ in asthma, in 2013 we performed pre-clinical studies using mouse models of acute allergic asthma.100 In these studies, we found that TCZ had a protective effect on allergen-induced airway inflammation only when the experimental model used resulted in increased levels of sIL-6R in the airways, and so that was likely to involve activation of the IL-6 trans-signaling pathway.