Signaling through the TLR2/TLR1 heterodimer was shown important in the induction of protective mucosal Th17 immune responses against infection (33), whereas intranasal treatment with the synthetic TLR2/TLR1 agonist Pam3Cys induced an expansion of the Treg cell population in the lungs in a mouse model of allergic asthma (34), TLR2/TLR6 receptor ligation by Yersinia pestis virulence factor LcrV and Yeast Zymosan, a ligand for TLR2/Dectin-1 both promoted tolerogenic dendritic cells (DCs), and the induction of Treg responses (35, 36). Here, TLR2 is linked to allergic asthma.