However, in an allergic model of murine asthma, IL-23 produced by dendritic cells (DCs) at the site of antigen sensitization facilitated eosinophilia and Th2 immune responses (DC-secreted IL-23 and Th2 cell interaction mechanism);24 in addition, increased IL-23 expression in the lungs upon antigen inhalation enhanced the recruitment of both eosinophils and neutrophils13. Here, IL23A is linked to asthma.