The development of second-generation CAR-T and the choice of CD19 as a tumour antigen significantly increased CAR-T activity in preclinical studies that were translated into unprecedented clinical results in B-cell acute lymphoblastic leukaemia (B-ALL) and non-Hodgkin lymphoma (NHL) [1,2,3,4,5,6,7,8,9]. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.