Analysis of transcriptional programs in CAR T cells with correlation to clinical response. (A) Involved serum free light chain (FLC) levels of patients with myeloma over time after CAR T-cell therapy (day 0 = CAR T-cell infusion), by group. Statistical significance is marked by asterisk and determined by Wilcoxon rank-sum test (P = .0113). (B) UMAP of T cells, with projection of annotated CAR T cells from TR and DR groups at different time points (days) after infusion. (C) Bar plot showing the sum of CAR T cells from 15 patients, by group, at different time points (days) after infusion. (D) Bar plots showing proportions of CAR T cells (mean ± SE) at different cell states, by group. Statistical significance is marked by asterisk and determined by Wilcoxon rank-sum test (P = .030) (E) Volcano plots showing differentially expressed genes between patient groups (DR vs TR) in CD4⁺ CAR T cells and CD8⁺ CAR T cells. Annotated genes in red have a statistically significant (P < .05) fold change (FC) >1.5. (F) Dot plots showing normalized expression of cytotoxicity and exhaustion genes in CD4⁺ and CD8⁺ CAR T cells, by group. Dot size is proportional to fraction of cells. MAIT, mucosa-associated invariant T cell; NKT, natural killer T cell.