A preparation of autologous T-lymphocytes that have been genetically modified to express a chimeric antigen receptor (CAR) targeting the tumor-associated antigen (TAA) CD19 and containing, as of yet undisclosed, costimulatory signaling domains, with potential immunostimulating and antineoplastic activities. Upon administration, relmacabtagene autoleucel target and bind to CD19-expressing tumor cells, thereby inducing selective toxicity in CD19-expressing tumor cells. CD19 antigen is a B-cell specific cell surface antigen expressed in all B-cell lineage malignancies.