TLR7 and asthma: It appears that each synthetic agonist exploits distinct mechanism and in this context, activation of TLR7 by 9-benzyl-2-butoxy-8-hydroxy adenine, a ligand for TLR7, could attenuate murine asthma restraining Th17 and Th2 responses (109), whereas R848 arrests the symptoms of established asthma through Treg cells (111).