CD19 and Thrombocytopenia: Regarding hematological toxicity, there was a significant difference in the incidence of severe thrombocytopenia (grade 3-4) among the single CD19, tandem CD19/CD22, and sequential CD19/CD22 groups (44.9%, 58.8% and 71.4%, respectively; P = 0.031) but no significant difference in the pairwise comparisons (Supplementary Table 5).