IL13 and asthma: In the constructed ovalbumin-induced acute rat asthma model, they found that the anti-inflammatory effect of FXR is achieved by blocking the infiltration of inflammatory cells into normal lung tissues, thereby inhibiting the secretion of IL-4, IL-5, and IL-13 by activated helper Th2 cells and that of tumor necrosis factor-α (TNF-α) by activated alveolar macrophages.