Based on the results of the pivotal ELIANA trial (ClinicalTrials.gov identifier: NCT02435849) (12) and subsequent approval of tisagenlecleucel, an anti-CD19 CAR-T product, for the treatment of CD19+ R/R BCP-ALL by the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) in 2017/18, a rapidly increasing number of paediatric stem cell transplantation centres have been certified to administer tisagenlecleucel to paediatric patients and AYAs, and hundreds of products have been infused worldwide as a novel standard-of-care treatment option. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.