Illustration of chimeric antigen receptor (CAR) T cells (blue) attacking diffuse large B-cell lymphoma (DLBCL) cells (purple). DLBCL is a common type of non-Hodgkin lymphoma, or cancer of the lymphatic system. It affects B lymphocytes, a white blood cell that produces antibodies to fight against infection. DLBCL normally develops in the lymph nodes causing uncontrollable growth of the B lymphocytes. It is typically fast-growing. CAR-T therapy is a type of immunotherapy that genetically modifies a patients own T cells, a form of white blood cell, to recognise and destroy cancer cells.