(A and B) Flow cytometric analysis of CD4⁺ and CD8⁺ thymocytes ex vivo developed for 3 days from sorted RORγt^–/– CD4^–CD8^– or WT CD4^–CD8^– in the presence of different concentrations of IMU-935 (A) (n = 2–4/group, from 4 experiments) or RORγt modulators (B) (1 μM; n = 4/group, from 4 experiments). Percentages of CD4⁺ plus CD4⁺CD8⁺ T cells among live Thy1.2⁺ thymocytes are shown. (C and D) Percentages of live cells among CD4⁺CD8⁺ thymocytes relative to the vehicle control different times after culture in the presence of indicated concentrations of IMU-935 (C) or RORγt modulators (D) (1 μM; n = 3/group, from 1 experiment). Thymocytes from RORγt^–/– mice were used as a control. (E) Picture and cellularity of the thymus from mice (n = 8–9/group; n = 8 for vehicle and IMU-935 groups, and n = 9 for Cpd-1 and cintirorgon groups) treated with vehicle or indicated RORγt inhibitors or cintirorgon (100 mg/kg orally, twice daily) for 28 days. (F) H&E staining (scale bar: 500 μm) of the thymus from mice treated as described in E. M, medullar; C, cortex. Bottom: The ratio of the medullary/cortical region. (G) Flow cytometric analysis of CD4 and CD8 in the thymocytes from mice treated as described in E. (H) TUNEL staining (top; scale bar: 500 μm) and percentage of TUNEL-positive apoptotic cells in thymus obtained from mouse treated as described in E. Bottom right: The qRT-PCR analysis of Bcl2l1 mRNA. (I) Number of alive, human CD4⁺CD8⁺ thymocytes cultured in the presence of indicated RORγt inhibitors (1 μM) for 24 hours (thymocytes collected from 1 donor, n = 3 replicates/group). Data were assessed by 1-way ANOVA with Dunnett’s post hoc test (A–H) or 2-tailed Student’s t test (I). *P < 0.05; **P < 0.01.