Single-cell transcriptional profiles of CAR T cells given either on day 0 or on day +5 and assessed 3, 8, and 16 days post infusion. Mice were transplanted as in Figure 5. At 3, 8, or 16 days after CAR T-cell infusion, recipient mice were euthanized and splenocytes pooled from 5 to 11 mice per group were flow cytometrically sorted for viable (LIVE/DEAD⁻) CAR T cells (Thy1.2⁺CD45.1⁺Protein-L⁺). Flow cytometrically purified CAR T cells underwent single-cell RNA sequencing with the 10× Genomics Chromium platform using the 5′ v2 gene expression chemistry targeting up to 6000 cells captured per sample. Combined data from 2 independent experiments are shown. (A-B) tSNE plots grouped by (A) treatment and time point or (B) unsupervised clustering are shown. (C-D) Clusters from panel B are shown subsetted based on (C) treatment and time point group or (D) putative T-cell differentiation type based on a prior publication.¹⁸ Th, T helper; Tfh, T follicular helper; Treg, T regulatory; tsne, t-distributed stochastic neighbor embedding.