CD19 and hematologic disorder: The introduction of CAR-modified HSPCs in the hematopoietic stem cell transplantation (HSCT) context, which is the standard of care for high-risk patients with CD19-positive hematological malignancies, would favor effective immune response against minimal residual malignancy, support the engraftment of modified cells, and reduce the possibility of immunogenicity of the CAR constructs on the surface of effector cells [223].