CD4CAR T-cell infusion products reveal correlates of successful Env boosting. Phenotypic differences in infusion products for groups 1 (A15104, A15112, red) and 2 (A15106, A15108, blue) were assessed by flow cytometry 8 days following after transduction, immediately before in vivo administration. (A) CAR⁺ cells. (B) CAR⁺Ki67⁺ cells. (C) CAR⁺CD69⁺ cells. (D) CAR⁺PD-1⁺TIGIT⁺ (T-cell immunoreceptor with Ig and ITIM domains) cells. (E) CD95⁺CD28⁺ memory CAR T cells. (F) CCR7^–CD45RA⁺ effector memory CAR T cells. CD8^–, surrogate for CD4⁺ T cells; SHIV^–, cells collected and cryopreserved before SHIV infection; SHIV⁺, cells collected with or without cryopreservation, following SHIV infection and stable suppression by ART.