In an allergic asthma model, co-administration of the TLR2 agonist Pam3CSK4 or the TLR9 agonist CpG with OVA during the intraperitoneal sensitization protected the mice from developing allergies via inducing monocytes to secret Th1 cytokines (Huang et al., 2018) Eisenbarth et al. demonstrated that high doses of LPS (100 μg/instillation/mouse) favored Th1 responses whereas low doses (0.1 μg/instillation/mouse) favored Th2 responses in a murine intranasal sensitization model using OVA. Here, TLR9 is linked to allergic disease.