A publication in 2011 of a pilot clinical trial for patients receiving B cell antigen CD19-directed CAR-T cell therapy for chronic lymphocytic leukaemia was followed by a 2013 publication from the same group for paediatric patients receiving CTL019 CAR-T cell therapy for acute lymphoid leukaemia (ALL) [2,3]. Here, CD19 is linked to acute lymphoblastic leukemia.