CD19 and neoplasm: Despite the significant advances in CAR-T therapiesagainst hematologic malignancies, the treatment of mostsolid tumours is still faced with serious challenges (3).One of the main reasons for this failure is the identificationof suitable tumour-specific antigens for solid tumours.Contrary to CD19, which is expressed solely on thesurface of B-lymphocytes, most tumour antigens forsolid tumours are found in healthy tissues, which can berecognized by redirected T cells and lead to "on-target offtumour"toxicities.