Dear all, I heard that renormalisability has something to do with the spin. A quantum field theory of particles with spin 0 or 1/2 is renormalisable; where with spin 1 is originally unrenormalisable, however, since we have gauge theory for the spin 1 particles, the symmetry cures the problem, and the field theory becomes renormalisable in the case of spin = 1. In this perspective, a field theory of spin 2 particles is unrenormalizable, like the quantum gravity. But I haven't read about this from the renormalisation sections of some books, like Ryder or Peskin. Is this related to the proof provided by 't Hooft? Or anyone can provide a correct and clear picture or explanation? Many thanks!