For instance, systematic analysis of vector integration sites in CD19 CAR T cells infused to patients with chronic lymphocytic leukemia (CLL) revealed that CAR T responders could be distinguished from non-responders by the pattern of genes disrupted by vector integration [259], but gene expression in pre-infusion T cells also differed between complete responders and non-responders [260]. The gene discussed is CD19; the disease is B-cell chronic lymphocytic leukemia.