CD19 and hematologic disorder: CD19, a surface protein highly expressed on most B-lineage lymphocytes and not on normal tissue outside the B-lineage [44], is the most thoroughly studied target in all of the hematological malignancy-associated antigens, and CD19-specific CAR-T cell therapy has demonstrated enormous efficiency in inducing endurable remissions of several hematological malignancies, including ALL, chronic lymphocytic leukemia (CLL), and NHL [45–47], with complete remissions (CR) in ALL at 90% and response rates in CLL greater than 50% [48, 49].