The percentages and/or numbers of viable (A), Ki67⁺ (B and C), and IFN-γ⁺ (D and E) cells were measured in activated CD8⁺ T cells as indicated. The percentages of viable PD-1⁺Lag-3⁺ (F), CD44⁺TCF1⁺ (G), and CD44⁺CD127⁺ (H) cells were measured in activated CD8⁺ T cells as indicated. Percentages of PD-1⁺Lag-3⁺ (I), PD-1⁺CD39⁺ (J), Ly108⁺CD69⁺ (K), CD127⁺ (N), or CD127⁺GPX4⁺ (O) cells among transferred cells in EG7 tumor infiltrates (n = 5) were measured 1 week after i.v. transfer of activated OT-1 CD90.1⁺CD8⁺ T cells. In parallel, infiltrating transferred T cells were sorted and measured for intracellular GSH and GSSG by HPLC. The GSH/GSSG ratio was calculated (L). Lipid ROS levels indicated by BODIPY FITC were also detected in transferred infiltrating T cells by flow cytometry (M). Tumor volume (P) and survival (Q) were measured in MC38-bearing mice (n = 5) with and without i.v. transfer of activated tumor-reactive CD90.1⁺CD8⁺ T cells as indicated. (R and S) EG7-bearing mice (n = 5) received i.v. transfer of activated OT-1 CD90.1⁺CD8⁺ T cells as indicated. Mouse survival was measured until day 200 (R). Tumor-free mice from R were rechallenged with EG7 cells, while naive mice received the same EG7 cells simultaneously s.c., and mouse survival was measured over time (S). Tumor volume (T) and weight (U) (on day 28) were measured in HCC-1806–bearing mice (n = 4) with activated anti-MSLN CAR T cells as indicated. Results are representative of 2 (F–H and P–S) or 3 (A–E, T, and U) independent experiments. Data were analyzed by 2-way ANOVA (A, C, E, F–O, T, and U) and log-rank test for survival curves (Q and R). Data plotted are mean ± SEM from biological replicates. *P < 0.05, **P < 0.01, ***P < 0.001.