CD19 is used as a target antigen because of its lineage selectivity and relatively universal expression on the cell surface of B cells and absence from hematopoietic stem/progenitor cells and non-hematopoietic tissues [114]; therefore, the CAR-T cells are able to target only cancer cells in B-ALL, minimizing the destruction of healthy cells [112]. Here, CD19 is linked to acute lymphoblastic leukemia.