CX3CR1 and asthma: As fractalkine induces lymphocyte chemotaxis, [23, 27] and RV infection induced high fractalkine production by PBMCs from asthmatics in our study, it is possible that fractalkine plays a pathogenic role by aiding chemotaxis of circulating CX3CR1+ cells involved in type 2 immunopathological responses into the bronchial mucosa during RV infection in asthma.