CD28 and diffuse large B-cell lymphoma: Due to their unprecedented success in multiple patients in clinical trials, the second generation CD19-CAR containing 4-1BB-CD3ζ (Tisagenlecleucel) was FDA approved for patients with B cell acute lymphoblastic leukemia in 2017 and diffuse large B cell lymphoma in 2018 while the second generation CD19-CAR containing CD28-CD3ζ (Axicabtagene ciloleucel) was approved for diffuse large B cell lymphoma in 2017 (7).