ILC2s are present at higher frequency and with a modified phenotype in the skin of AD patients. (A) Frequency of ILC2 (as a percentage of IL-7Rα⁺ cells) in the blood and skin of healthy controls (HCs; n = 15) or in lesional biopsies of the acutely affected skin of patients with AD (n = 8) was measured by flow cytometry. (B–D) ILC2s (Lin⁻CD45^highIL-7Rα⁺) were isolated from the skin of patients with AD and healthy controls, and expression of ST2 (B), IL-17BR (C), and TSLPR (D) was analyzed by flow cytometry. Representative flow plots are shown on the right. Numbers indicate percentages of cells within the top right quadrant of gated populations. B: patients and controls (n = 7); C: patients (n = 5), controls (n = 8); D: patients (n = 6), controls (n = 7). (E) Acute lesional skin biopsies were taken from patients with AD (n = 8) and healthy controls (n = 6), and expression of IL1RL1 (IL-33R), IL-33, IL17BR, IL-25, CRTH2, TSLPR, AREG, and RORA was measured by RT-PCR relative to GAPDH. *, P < 0.05; **, P < 0.01; ***, P < 0.001, unpaired Student’s t test (mean and SEM in A and E; min and max in B–D).