There certainly are a lot of variables that will come into play. In haematological malignancies, even if T-cells get transduced (leaving aside off-target transduction), the percentage that do, and the number that will have the right phenotype to be effective could be low, which would be a bottleneck. So getting it to work in a reproducible fashion is unknown. Toxicity is another concern, at least with the data shared from one ongoing trial. Things will be ever more challenging in solid tumours. This leaves autoimmune diseases as a more tractable target, at least in the short term.