IL13 and asthma: Additionally, in vivo administration of PD-L2 in mouse asthma models led to increased serum IgE levels, eosinophil and lymphocyte infiltration into the bronchoalveolar lavage fluid, increased cell counts in draining lymph nodes, and production of IL-5 and IL-13 in tissues, indicating that PD-L2 may contribute to asthma exacerbation [75].