Non-Hodgkin's lymphoma (NHL) is a group of cancers caused by uncontrolled proliferation of lymphocytes. Its most common type (about 85%) is B-cell lymphoma. There are several subtypes of B-cell lymphoma, all caused by uncontrolled proliferation of B-cells (B lymphocytes). B-cell lymphoma is conventionally treated through chemotherapy, radiotherapy, and immunotherapy.

Despite the different types of treatments available, B-cell lymphomas still have high rates of relapse and low survival rates following relapse. This grave outcome demands the development of new treatment approaches.

The T-cell chimeric antigen receptor is a transmembrane fusion protein with an extracellular region binding the target antigen. CD19, a protein located on the surface of human B-cells, is one of the most targeted antigens. It is a convenient recognition element for these cells—particularly when they are abundant due to uncontrolled proliferation. The T-cell chimeric antigen receptor also contains an intracellular co-stimulatory region (CD28 or 4-1BB), which enhances the function of an additional intracellular protein region, CD3-zeta. Upon binding of the extracellular region to CD19, CD3-zeta triggers intracellular T-cell responses, causing cytotoxicity against B-cells. When present on the surface of T-cells, this chimeric antigen receptor is a powerful molecular tool to combat proliferating B-cells.

In clinical trials, adverse side effects are usually graded on a scale from 1 (not bothersome) to 5 (fatal). Grade 3 adverse effects are severe, can affect the patient's autonomy, and require medical care.