Currently, four autologous CD19-directed CAR T-cell therapies have gained approval by the U.S. Food and Drug Administration (FDA) for the treatment of relapsed or refractory diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma, high-grade B-cell lymphoma, and transformed follicular lymphoma, while further CAR T-cell immunotherapies have entered the clinical trials pipeline. The gene discussed is CD19; the disease is B-cell non-Hodgkin lymphoma.