CAR‐T therapy is so effective in treating hematomas malignancies, mainly diffuse large B‐cell lymphoma and B‐cell acute lymphoblastic leukemia, because CD19 and CD20 are relatively tumor‐specific antigens (TSAs) expressed in many of these cancers, making the targeted antigens CAR‐T more effective. This evidence concerns the gene CD19 and B-cell acute lymphoblastic leukemia.