A recent study conducted by Quoc et al. also found increased levels of S100A9 in bronchoalveolar lavage fluid and lung tissues in asthma mouse models, which further promotes the activation of RAGE-dependent pathways such as ERK, p38 and NF-kB, thus perpetuating airway inflammation/remodeling and contributing to the progression to severe asthma [175]. Here, S100A9 is linked to asthma.