There is increasing evidence indicating that activation of peroxisome proliferator-activated receptor gamma (PPARγ) by its ligands can inhibit the growth of thyroid cancer, likely via multi-mechanisms including stimulation of the anti-tumor immune system, induction of cancer cell differentiation, increase of radioiodine uptake in thyroid cancer cells, cell cycle arrest, and promotion of apoptosis of cancer cells (1–12). Here, PPARG is linked to thyroid cancer.