Chimeric antigen receptors (CARs) are hybrid proteins consisting of an antibody binding fragment fused to protein signaling domains that cause T-cells which express the CAR to become cytotoxic. Once activated, these cytotoxic T-cells can selectively eliminate the cells which they recognize via the antibody binding fragment of the CAR. Thus, by engineering a T-cell to express a CAR that is specific for a certain cell surface protein, it is possible to selectively target those cells for destruction. This promising new therapeutic approach is known as adoptive cell therapy. CD22 is a cell surface protein expressed on a large number of B-cell lineage hematological cancers, such as leukemia and lymphoma. Several promising therapies are being developed which target CD22, including therapeutic antibodies and immunotoxins. This technology concerns the use of a high affinity antibody binding fragment to CD22 (known as m971), as the targeting moiety of a CAR. The resulting CAR can be used in adoptive cell therapy treatment for cancer.