Adult mLNSCs have a history of FAP expression. (A) Schematic of FC^Tomato mice. (B) tdTomato expression in FC^Tomato and C^Tomato iLN sections. (C–F) tdTomato expression by cells from mesLNs (C and E) or pLNs (D and F) from FC^Tomato mice. (C and D) Phenotype of tdTomato⁺ cells. SSC, side scatter. (E and F) tdTomato expression and tdTomato mean fluorescence intensity (MFI) in LN cells. Data represent three independent experiments with four to six mice. Statistical significance was determined by one-way ANOVA, compared with the CD45⁺ group, *, P < 0.001; ns, not significant. (G–O) tdTomato⁺ mLNSCs were identified in iLN sections of FC^Tomato mice: FRCs (G), FDCs (H), MRCs (I), interfollicular and T:B border mLNSCs (J), medullary mLNSCs (K), CD34⁺ adventitial cells (L), CD34⁺ capsular mLNSCs (M), CRCs in mice immunized 14 d before (N), and perivascular DNCs (O). In O, arrow denotes ITGA7⁻tdTomato⁺ FRC; arrowheads denote ITGA7⁺tdTomato⁺ perivascular cells. (P) tdTomato expression in mLNSCs from FC^Tomato mice, C^Tomato mice, and FC^Tomato (+dox e0) mice. Data are compiled from three experiments comprising three to four mice per group. Statistical significance was determined by one-way ANOVA comparing all groups to each other, **, P < 0.0001; ns, not significant. Scale bars, 500 µm (B); 100 µm (J–N); 50 µm (G–I and O). Images represent more than five mice.