Cellular characteristics of the final CAR–T-cell product. (A) The final product of CAR-expressing T cells showed mainly T_cm and T_em T cells regardless of TCR expression after expansion (n = 3). (B) Surface expression profile of several costimulatory (OX40, CD28, 4-1BB) and coinhibitory molecules (PD-1, TIM-3, BTLA, CTLA-4, TIGIT, VISTA) as well as commonly used exhaustion markers (2B4, LAG-3, PD-1) was determined by flow cytometry and compared between CAR T cells with or without TCR KO (n = 3). (C) Cellular composition of CAR T cells was determined on day 14 (n = 4). A 2-tailed paired Student t test was performed to determine statistical significance. T_cm, CD62L⁺, CD45RO⁺, CD95⁺; T_em, CD62L⁻, CD45RO⁺, CD95⁺; T_eff, CD62L⁻, CD45RO⁻, CD95⁺; T_n, CD62L⁺, CD45RO⁻, CD95⁻; T_scm, CD62L⁺, CD45RO⁻, CD95⁺. n.s., not significant; T_n, naïve T cells; T_scm, stem cell-like memory T cells.