Depletion of ILC2 significantly reduces ear swelling and inflammation in mice. MC903 or vehicle was applied topically for 4 d to the ear of Rag1^−/− mice with or without prior treatment of anti-CD90.2 antibody or isotype control. In A, B, D, and E, vehicle is shown as open bars and MC903 is shown as filled bars. Accumulation of LN ILC2 (A); total LN cell number (B); and increase (percent) in ear thickness after MC903 application (C). After 4 d of topical application of MC903 or vehicle to the ear of wild-type or Rora^sg/sg bone marrow chimera mice, the accumulation of LN ILC2 (D), total LN cell number (E), and increase (percent) in ear thickness (F) were documented. n = 5–6 mice per group. Data are representative of two independent experiments. *, P < 0.05; **, P < 0.01; ***, P < 0.001, unpaired Student’s t test with Welch’s correction (mean and SEM).