PAX8 and neoplasm: A common mutation found in anaplastic thyroid canceris a PAX8/PPARγ rearrangement which results in downregulationof PPARγ, suggesting that PPARγ may be a tumor suppressor gene in this type ofcancer [59].In addition, the fusion protein, PAX8-PPARγ, resulting from this rearrangement can act asa dominant negative inhibitor of wild-type PPARγ [66].Treatment with the novel PPARγ agonist RS5444 in anaplastic thyroid cancercells lines resulted in growth inhibition and PPARγ activation.