CD19 and cancer: Cancer immunotherapy has shown remarkable results in certain cancers which had poorer outcomes, especially in childhood acute lymphoblastic leukaemia, where CAR T-cell therapy targeting B-cell antigen (CD19) [9–13] led to an overall remission rate of 82.5% [14, 15], and in advanced melanoma, where cytotoxic T lymphocyte antigen 4 antibody improved the overall survival and 5-year recurrence-free survival [16, 17].