It's more of a regulatory rigour than a hurdle. We are required to make sure there is comity: Are their regulatory requirements and tests the same? We need to really make sure that we can trust that. It is a longer process. We get to know their scientific review teams.
It's worth saying, though, that the way we've made the proposal is that as soon as we are okay with the company, we can add it by an incorporation by reference. We don't have to make a regulatory change; we can just put it right on the list when we're ready.