Similarly, T cells transduced with a anti CD19 CAR containing the 4-1BB and CD3ζ signaling domains (CD19-BBz) exhibited prolonged in vivo persistence and expansion, correlating with sustained clinical benefit in individuals with R/R B-ALL (16) and chronic lymphocytic leukemia (CLL) (14). This evidence concerns the gene CD19 and B-cell chronic lymphocytic leukemia.