CD19 and leukemia: Memory CAR T cells have been manufactured for clinical use already in hematopoetic malignancies such as leukemia; Wang et al. (155) used a protocol using magnetic separation to select CD8+ CD45RA+ CD62L+ TCM cells to transduce with a CD19 CAR while culturing with IL-2 and IL-15, and several variations of these CARs (which have CD28 costimulatory domains) are being tested in a phase I study.