Annotated CAR T cells from 15 patients with myeloma, their cell states, and TCR clonality. (A) Scheme showing annotation of CAR T cells by de novo transcriptome assembly and targeted amplification. (B) UMAP of 690 939 T cells with projection of annotated CAR T cells (n = 100 157). (C) Fraction of CD4⁺ and CD8⁺ CAR T cells over time (mean ± standard error [SE]). (D) Bar plot showing proportions of annotated CAR T-cell states. Significance level was determined using Wilcoxon rank-sum test (P < .001). (E) Gini coefficients (mean ± SE) for non-CAR T cells and CAR T cells, by CD4⁺ and CD8⁺, over time. Baseline represents before CAR T-cell infusion; early, day 14 and day 30 after infusion; and late, day ≥90 after infusion. (F) Pie charts of expanded CAR T-cell clonotypes (same TCR clonotype in >1 cell), by CD4⁺ and CD8⁺. MAIT, mucosal-associated invariant T cell; NKT, natural killer T cell.