CD19 and acute lymphoblastic leukemia: Based on cancer type and CAR-T type, we classified the 84 identified studies into 18 different categories: 12 for hematological malignancies including CD19-NHL, CD19-ALL, CD19-ALL/NHL, CD20-NHL, CD22-ALL, CD30-HL, CD33-HL, leY-AML, LCAR-B28-MM, BCMA-MM, NKG2D-MM/AML/MDS, and specific CD19; and 6 for solid tumors including CEA, EGFR, GD2, HER2, methesolin, and TAG-72.