Chimeric antigen receptor T cell therapy – often called CAR T cell therapy – is a type of cancer treatment used to treat children and young adults with acute lymphoblastic leukemia and adults with large B-cell non-Hodgkin lymphoma. With this type of immunotherapy, T cells are extracted from the patient and modified in a laboratory to express the chimeric antigen receptor, which allows the cells to better recognize and fight cancer. The modified cells are then expanded to large numbers and returned the patient through an IV to begin attacking the cancer.