Flow cytometric analysis of ectoenzyme expression on ILC across different tissues. (A) Gating strategy for flow cytometric analysis of human ILC from healthy peripheral blood, with ILC defined as: Lin⁻ (CD1a, CD3, CD4, CD8, CD14, CD16, CD19, CD34, CD94, CD123, BDCA2, FcεRI, TCRαβ, TCRγδ), CD45⁺ CD127⁺CD161⁺ cells. From this population, CRTH2⁺ cells define ILC2; CRTH2⁻CD117⁻NKp44⁻ cells define ILC1, and CD117⁺ cells define ILC3. (B) CD39-CD73 and CD38-CD73 expression by ILC3 freshly isolated from fetal intestine and mLNs, cord blood, adult peripheral blood, healthy bone marrow, and tonsils. Contour plots are representative of 2 to 3 independent experiments. (C) Contour plot showing CD39⁻CD73⁻ (DN) ILC3 and CD39⁺CD73⁺ (ecto⁺) ILC3 gating in tonsils, and the bar graph shows the frequency of CD39 and CD73 on total tonsillar ILC3 (n = 25); each symbol represents an individual donor, error bars show the standard error of the mean (SEM), and the horizontal lines represent the mean.