C5AR2 and allergic asthma: Together with in vitro studies of HDM-pulsed bone marrow-derived DC cells (mDCs), Zhang and colleagues suggested that C5aR2 might play complex dual roles in experimental allergic asthma—suppressing Th1 and Th17 differentiation through mDCs/T cells while inducing Th2 differentiation through other pulmonary cells [65].