TQFTs do not detect the Milnor sphere

I will talk about the recent paper of Gripaios and Randall-Williams with that title, where they prove that a functorial TQFT (i.e. a symmetric monoidal functor from the n-dimensional bordism category into a suitably nice target category) assigns the same value to homotopy spheres that bound a parallelizable manifold, extending some no-go theorems of Reutter and Schommer-Pries.