CD19 and cancer: Neurotoxicity, also termed immune effector cell-associated neurotoxicity (ICANS)6 occurs in ∼40% of patients receiving CD19-directed CAR T cells and is also seen after CD22- and B-cell maturation antigen-CAR treatment.7–9 We should note that in the oncology field, the term ‘neurotoxicity’ is used as a clinical descriptor of neurologic adverse events following cancer treatment, and is not meant to specifically imply neuronal cellular injury, though it is a facet of the injury.