In various hematologic malignancies such as B-cell acute lymphoblastic leukemia (B-ALL), R/R non-Hodgkin lymphoma (R/R NHL), and R/R B-cell lymphoma, bispecific CAR-T cells targeting a second antigen in addition to CD19 (such as CD20 or CD22) have been extensively explored and applied in both preclinical and clinical settings to prevent antigen escape-related relapses [43–45, 47–49]. The gene discussed is CD22; the disease is acute lymphoblastic leukemia.