Here, CD22/CD19 sequential therapy was effective in inducing MRD-negative CR in 4/4 (100%) B-ALL patients with moderate CRS, including 3 patients who previously received CD19 CAR-T therapy or blinatumomab and 3 patients with genetic lesions including BCR-ABL, TP53 loss and IKZF1 deletion. The gene discussed is CD22; the disease is acute lymphoblastic leukemia.