One pilot study (ChiCTR, number ChiCTR-OPN-16008526) conducted in 89 refractory/relapsed (r/r) B-cell malignancy patients (51 acute lymphoblastic leukemia patients and 38 non-Hodgkin lymphoma patients) showed that the sequential infusion of anti-CD19 and anti-CD22 CAR-T cells (CAR19/22 T cell cocktail) exhibited a remarkable anti-tumor effect (median progression-free survival: 13.6 months and 9.9 months, respectively) and safety (high-grade CRS and neurotoxicity: 22.4% and 1.12% patients, respectively). Here, CD19 is linked to acute lymphoblastic leukemia.