To further characterize CAR-T-cell effects on tumor growth beyond RT-qPCR analysis, tumor tissues in the negative control (“Raji, NO CAR-T”) and in the groups treated with CD19 CAR-T (CD3z-CD28) (“Raji + CAR-T E11” and “Raji + CAR-T E11/E14”) were analyzed by hematoxylin and eosin (H&E) staining (Figure 5a). The gene discussed is CD28; the disease is neoplasm.