At the time of writing this paper Tisagenlecleucel (Kymriah, Novartis), an autologous CD19-CAR Tcell, is approved by the US Food and Drug administration (FDA) and other governmental bodies for use in children and young adults for relapsed or refractory CD19+ B ALL, including post HSCT relapse. Here, CD19 is linked to acute lymphoblastic leukemia.