CD19 and acute lymphoblastic leukemia: In February 2021, the ‘Advanced Therapy Medicinal Product’ (ATMP) ARI-0001 (CART19-BE-01, an anti-CD19 CAR [Chimeric Antigen Receptor or CAR19] against CD19+ B-cell malignancies) received authorisation from the Spanish Agency of Medicines and Medical Devices (AEMPS) under ‘hospital exemption’ (HE) for the treatment of adult patients (>25 years old) with relapsed/refractory (R/R) acute lymphoblastic leukaemia (ALL) [1].