A 4-gene signature in leukapheresis products correlate with survival of patients with lymphoma receiving CAR T-cell therapy. (A) Heat map clustering of patients based on the expression of the 4 genes in CD3⁺ selected cells (n = 77). After separation, median CD3⁺ population purity was 98.2%. Ward and Canberra were used as linkage and distance metrics, respectively. Patients’ features are shown alongside the code (ASCT, CRS, classification C₁₀, ECOG, ICANS, ICI, IPI, LoT, and PFS). (B) Kaplan-Meier estimate of PFS in patients stratified according to the 4-gene model (n = 77). SIG^pos, 4-gene signature positive (group 1), SIG^neg, 4-gene signature negative (group 2). (C) Percentage of CAR+CD8+T_CM cells in IPs of SIG^pos and SIG^neg (n = 58). (D) Concentration of CAR T cells at day 10 after infusion (C₁₀) in SIG^pos and SIG^neg (n = 72). In panels C-D, exact median values are reported, Mann-Whitney test was used for comparisons. ∗∗P < .01. ASCT, autologous stem cell transplantation; CRS, cytokine release syndrome; classification C₁₀, classification of expanders and poor-expanders patients according to the number of circulating CAR T cells at day 10 after infusion (C_10, patients were dichotomized into expanders and poor-expanders using the median C10 as cutoff); ECOG, Eastern Cooperative Oncology Group performance status; ICANS, immune-effector-cell–associated neurotoxicity syndrome; ICI, immune checkpoint inhibitors; IPI, international prognostic index; LoT, lines of therapies before leukapheresis.