In a study of CAR T-cell (tisagenlecleucel) therapy in 41 patients with chronic lymphocytic leukemia (CLL), sustained remission was seen in patients with increased CD27+CD45RO−CD8+ T cells, with memory-like characteristics, measured in blood by flow cytometry prior to CAR T-cell infusion [38]. This evidence concerns the gene CD27 and B-cell chronic lymphocytic leukemia.