CD8A and acute lymphoblastic leukemia: In contrast, by tracking SJCAR19 CAR T cells longitudinally in 16 pediatric B-acute lymphoblastic leukemia (ALL) cases before and up to 6 months after infusion using their native TCR sequences as clonal barcodes, Wilson et al. found that TIGIT expressing effector precursor CD8+ CAR T cells constitute a subpopulation within infusion products that has superior functionality and is less prone to acquire an exhausted phenotype.128