We further demonstrate that CD200R engagement inhibits both the canonical and non-canonical NF-κB pathways in activated ILC2s, as evidenced by downregulation of pIKKα/β, Nfkb1, and Rela (p65), as well as Nfkb2 (p52) and Relb. Using a CD200-Fc, we showed that CD200R engagement on lung-derived ILC2s both protects against development of asthma, and is capable of therapeutically reversing established AHR in various mouse models. Here, RELA is linked to asthma.