T cells expressing chimeric antigen receptors (CARs) targeting CD19, CD20, CD22 and CD30 were able to kill around 50% of different B cell lymphomas in cell culture, and have provided spectacular results in clinical trials, with 60% of B cell lymphoma and leukemia patients in complete remission after treatment (219–223). The gene discussed is CD22; the disease is B-cell non-Hodgkin lymphoma.