Autologous CAR T-cell therapy demonstrated promising results in a series of clinical trials against chronic lymphocytic leukemia [85,86,87], B-ALL [87,88,89,90,91,92], and diffuse large B-cell lymphoma [92,93,94,95,96,97,98,99], leading to the Food and Drug Administration (FDA) and European Medicines Agency (EMA) approval of two autologous anti-CD19 CAR T drugs, namely KymriahTM [100,101,102] and YescartaTM [103,104]. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.