CD19 and acute lymphoblastic leukemia: In light of the results of the phase 3 COG AALL1331 trial that showed superiority of blinatumomab compared to chemotherapy as post-reinduction therapy in first relapse of B-ALL in children and AYAs, as well as ongoing studies utilising blinatumomab in the upfront setting, a number of patients will potentially be exposed to blinatumomab before anti-CD19 CAR-T cell therapy [70].