CD19 and congenital rubella syndrome: This observation is in line with recent reports highlighting that CAR-T cells including the CD28 costimulatory domain appear more likely to induce CRS and neurotoxicity in patients than products containing 4-1BB.46–50 However, besides costimulatory domains, CD19 CAR-T cell products also differ for several other parameters that can impact toxicity development, such as manufacturing procedure and target populations, challenging the possibility of making direct comparisons on available data.