CD19 and cancer: It has shown limited success in multiple solid malignancies due to a lack of tumour infiltration and proliferation.14 In addition to the immunosuppressive tumour microenvironment limiting immune cell infiltration, acquired mutations by cancer cells may provide additional escape mechanisms to prevent T cell and NK cell attack.18 CAR-T cells are engineered to express a receptor specific to an antigen on the surface of cancer cells, such as CD19.