Fate mapping of Il17rb⁺ cells via Il17rb-CreERT2-eGFP mice crossed to an RFP reporter. (A) Representative flow cytometry plots showing Lineage⁻ Il17rb-eGFP⁺ (CD4⁻CD8⁻) cells in the SI-LP marked with RFP following tamoxifen administration. (B) Percentage of RFP⁺ ILC2s in the SI (n = 6 mice). (C) Representative histogram of RFP expression in BM ILC2s. (D) Percentage of RFP⁺ ILC2s in the BM following tamoxifen administration (n = 4 mice). (E) Representative flow cytometry plot showing Il17rb⁺RFP⁺ cells (IL-25R⁺KLRG1⁺ ILC2s) and ex-Il17rb⁺ cells in the SI 14 days after tamoxifen treatment. (F) Representative flow cytometry plot of ex-Il17rb⁺ cells, showing a SSC-A^highCD11b⁺ eosinophil phenotype. (G) Percentage of RFP⁺ eosinophils within CD64⁻CD11b⁺SSC-A^high eosinophils in the SI 14 days after tamoxifen treatment (n = 6 mice). (H) Quantification of RFP⁺ cells in the thymus and representative flow cytometry plots of RFP⁺ cells gated on CD4 and CD8 following five consecutive tamoxifen doses, with analysis at 14, 30, and 60 days after treatment (n = 3–5 mice). (I) Representative flow cytometry plots of CD8⁺ T cells in the SI and RFP expression. (J) Quantification of RFP⁺ cells within CD8⁺ T cells in the SI at 14 and 30 days after tamoxifen treatment (n = 6 mice). (K) Flow cytometry plots of CD4⁺ T cells in the SI and RFP expression. (L) Quantification of RFP⁺ CD4⁺ T cells in the SI at 14 and 30 days after tamoxifen treatment (n = 6 mice). (M) Representative flow cytometry plots comparing RFP expression in ILC2s versus Tregs in the SI 30 days after tamoxifen administration. WT refers to tamoxifen-treated Il17rb-CreERT2-eGFP mice, while Tg refers to tamoxifen-treated Il17rb-CreERT2-eGFP × R26R-flox-STOP-flox RFP mice. Data from all panels are representative of three or more independent experiments and are presented as the mean ± SEM.