CD19 and acute lymphoblastic leukemia: Recent advancements in ALL therapy have introduced immunotherapeutic approaches such as monoclonal antibodies (mAbs) (e.g., blinatumomab, inotuzumab ozogamicin) and chimeric antigen receptor (CAR) T-cell therapies (e.g., tisagenlecleucel, brexucabtagene autoleucel), targeting CD19-expressing B cells in relapsed or refractory cases [5-8].