Autologous T cells are gene-modified to express a dual-target chimeric antigen receptor recognizing CD19 and CD22 on B-lineage cells. Antigen engagement triggers CAR signaling (CD3ζ with costimulation), inducing T-cell cytotoxicity and cytokine release to eliminate malignant B lymphoblasts; dual targeting is intended to reduce antigen-escape relapse and leads to on-target B-cell depletion.