Blincyto (Blinatumomab), bridging CD3 on T cells and CD19 on B cells, was first approved in 2014 for Philadelphia chromosome negative (Ph‐) relapsed or refractory B‐cell precursor acute lymphoblastic leukemia (ALL), based on a single‐arm phase 2 trial that showed 33% complete response rate (NCT02000427), and then expanded to Ph+ patients and patients in remission with minimal residual disease in 2017 and 2018, respectively. This evidence concerns the gene CD19 and acute lymphoblastic leukemia.