NOS2 and neoplasm: As ligand-mediated PPARγ sumoylation suppresses the expression of inducible nitric oxide synthase (iNOS), a well-known proinflammatory enzyme that generates nitric oxide, and the anti-inflammatory role of PPARγ is believed to contribute to its tumor suppressive function of that receptor [34], we tested whether PPARγ sumoylation is critical for the anti-tumorigenic function of that receptor in the HBEC progression series.