The $\mathcal {OSP}(2,2|16)$ superconformal theory is free!
  The SuperConformal theory in three space-time dimensions with SO(16) $R$-symmetry, 128 bosons, and 128 fermions, cannot sustain interactions. This result is obtained using both light-cone superspace techniques which rely on algebraic consistency, and covariant methods which rely on SO(16) Fierz identities which fail to produce the desired algebra. 
Dmitry Belyaev, Patrick Hearin, and Pierre Ramond
hep-th