This approach proved effective in leukemia, where a CD19-specific CAR, composed of an extracellular single-chain variable fragment antibody fused to cytoplasmic signaling domains, triggers cytotoxic T-cell reactions upon contact with CD19+ B-lymphocytes, which results in specific and permanent elimination of the respective B-lymphocytes, yielding durable remission (102). The gene discussed is CD19; the disease is leukemia.