CD19 and acute lymphoblastic leukemia: As clinical proof of concept, TALEN-mediated TRAC/CD52 KO CD19 CAR T cells (UCART19) were administered to two infant patients with relapsed acute lymphoblastic leukemia (ALL), both of whom presented tumor remission, which was followed by successful allogeneic stem cell transplantation (allo-SCT), with no significant GVHD observed (73).